Milling Work piece (Basic)

Worksheet 2.2.2: Introduction to Milling Machine

2. What is the difference between a vertical milling machine and a horizontal milling
machine?
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Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 2.3.1: Basic functions of Milling Machine

Learning outcomes:
2 Determine job requirements
Learning Activity:
2.3 Identify the basic functions of Milling Machine

A. BASIC FUNCTIONS OF MILLING MACHINE

Operations done in milling machine are different from operating the machine tool. The
machinist is said operating the machine by using and adjusting the components of the
machine to achieve certain operation.

PRECAUTIONS WHEN OPERATING THE MILLING MACHINE

1. Avoid performing a machining operation on the milling machine until you are thoroughly
familiar with how it should be done.

2. Some materials that are machined produce chips, dust-, and fumes that are dangerous
to your health. NEVER machine materials that contain asbestos, Fiberglass, beryllium,
and beryllium copper unless you are fully aware of the precautions that must be taken.

3. Maintain cutting fluids properly. Discard them when they become rancid or
contaminated.

4. Be sure the cutter rotates in the proper direction. Expensive cutters can be quickly
ruined.

5. Carefully store milling cutters, arbors, collets, adapters, etc., after each use. They can
be damaged if not stored properly.

6. Never start a cut unless you are sure there is adequate clearance on all moving parts.
7. Carefully read instructions when using the new synthetic oils, solvents, and adhesives.

Many of them dangerous if NOT handled correctly.
8. Use adequate ventilation for jobs where dust and fumes are a hazard. Return oils and

solvents to proper storage. Wipe up spilled fluids. Do NOT pour used coolants, oil,
solvents, etc., down a drain.

ELEVATING THE KNEE

Raising and lowering the knee is done to establish
the proper elevation of the workpiece under the
cutting tool. This is mostly done to attain specific
depth of cut during operation.

 When the machinist turns the vertical hand
wheel clockwise the knee will go upward.

 While if it is turn counter clockwise the knee
goes downward.

FIGURE A.1

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 2.3.1: Basic functions of Milling Machine

 Set the graduated collar into zero (0) if the cutter just touches the surface of the
workpiece.

 Machine the surface of the workpiece and adjust the elevation by looking the collar
after first cut.

MOVING THE TABLE ACROSS THE COLUMN FIGURE A.2

Transverse table movement is movement of
saddle and table toward or away from the
column.

 When the machinist turns the cross feed
hand wheel clockwise the table will move
toward the column face.

 While if the cross feed hand wheel turns
counter clockwise the table will move
away from the column.

 Set the graduated collar into zero (0) if
the cutter just touches the surface of the
workpiece.

 Machine the necessary part of the
workpiece parallel to the direction of the table.

MOVING THE TABLE ALONG THE COLUMN FIGURE A.3

Longitudinal table movement is table travel from
side to side, toward either the right of the left.

 When the machinist turns the table hand
wheel clockwise the table will move to
the left of the column face.

 While if the table hand wheel turns
counter clockwise the table will move to
the right of the column face.

 Set the graduated collar into zero (0) if
the cutter just touches the surface of the
work piece.

 Machine the necessary part of the work
piece parallel to the direction of the table.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 2.3.1: Basic functions of Milling Machine

ADJUSTING THE SPINDLE SPEED
The spindle is designated in rpm (revolution per minute). It is necessary to adjust the
spindle speed according to the desired operation. It considers the cutting tool and work
piece material to avoid breakage of cutter during operation.

 The operator must understand that when the belt is placed in the largest pulley of the
driver (motor) and connected to the smallest pulley of the driven (spindle), the
spindle speed is in low speed. When the connection of the pulleys is in the vise
versa the speed is set to the highest speed.

USING THE QUILL LEVER
This movement is almost the same with
elevating the knee. They are used to
machine the workpiece with specific depth of
cut.

 The operator may use this lever for
more precise depth of cut. This lever
is automatically returns to its initial
position therefore the operator may
just turn it counter clockwise for down
feeding.

MILLING MACHINE CARE

1. Check and lubricate the machine with the recommended lubricants.
2. Clean the machine thoroughly after each job. Use a brush to remove chips. Never

attempt to clean the machine while it is running.
3. Keep the machine clear of tools.
4. Check each setup for adequate clearance between the work and the various parts of the

machine.
5. NEVER force a cutter into a collet or holder. Check to see why it does not fit properly.
6. Use a sharp cutter. Protect your hands when mounting it.
7. Have ALL guards in place before attempting to operate a milling machine.
8. Start the machining operation only after you are sure that everything is in satisfactory

working condition. It may be necessary to make special fixtures to hold odd shapes and
difficult to mount work.
9. Use attachments designed for the machine.

WARNING! Do NOT attempt to feel the machined surface while the cut is in progress or
while the cutter is rotating. Stop the machine before making measurements and
adjustments.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.1.1: Work holding Devices

Learning outcomes:
3 Setup work piece
Learning Activity:
3.1 Identify the types and functions of work holding devices for milling machine

WORK HOLDING DEVICES

A. VISES

These are most widely used work-holding devices for milling. They can be sued for holding
square, round, and rectangular pieces for the cutting of keyways, grooves, flat surfaces,
angles, gear racks and T-slots. Milling vises are manufactured in three styles.

 Plain vise FIGURE A.1

These may be bolted to the table so that its jaws are
parallel or right angles to the axis of the spindle. The
vise is positioned quickly and accurately by keys on the
bottom which fit into the T-slots on the table.

 Swivel vise

This is similar to the plain vise, except that it has a
swivel base which enables the vise to be swiveled
through 360 degrees in horizontal plane.

 Universal vise FIGURE A.2

This may be swiveled through 360 degrees in a
horizontal plane and may be tilted from 0-90 degrees in
vertical plane. it is used chiefly by tool makers, mould
makers, and die-makers, since it permits the setting of
compound angles for milling.

FIGURE A.3

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.1.1: Work holding Devices FIGURE B.1

B. DIVIDING HEAD

This is very useful accessory permits the cutting of bolt
heads, gear teeth, and ratchet. When connected to the
lead screw of milling machine, it will revolve the work as
required to cut helical gears and flutes in drills and
reamers, etc.

C. V-BLOCKS
Usually have 90 degrees v-shaped groove and tongue
which fits into the table slot to allow proper alignment
for milling special shapes, flat surfaces, or keyways in
round work. This is primarily used to rest the cylindrical
object in able to machine the center if necessary.

D. CLAMPS FIGURE C.1
FIGURE D.1
These are used when work cannot be held in a vise or
fixtures. It is often clamped to the table. Clamps are
held in position by a T-bolt that fits into T-slot of the
table. One end of the clamp is supported by the work
and the other end by a step block should be slightly
higher that the workpiece.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

Learning outcomes:
3 Setup work piece
Learning Activity:
3.2 Identify the types and functions of cutting tools, attachments and accessories for

milling machine

A. MILLING CUTTERS

Milling Cutter Nomenclature

This shows two views of a common milling cutter with its parts and angles identified. These
parts and angles in some form are common to all cutter types.

 The pitch refers to the angular distance between like or adjacent teeth.
 The pitch is determined by the number of teeth. The tooth face is the forward facing

surface of the tooth that forms the cutting edge.
 The cutting edge is the angle on each tooth that performs the cutting.
 The land is the narrow surface behind the cutting edge on each tooth.
 The rake angle is the angle formed between the face of the tooth and the centerline

of the cutter. The rake angle defines the cutting edge and provides a path for chips
that are cut from the workpiece.
 The primary clearance angle is the angle of the land of each tooth measured from a
line tangent to the centerline of the cutter at the cutting edge. This angle prevents
each tooth from rubbing against the workpiece after it makes its cut.
 This angle defines the land of each tooth and provides additional clearance for
passage of cutting oil and chips.
 The whole diameter determines the size of the arbor necessary to mount the milling
cutter.
 Plain milling cutters that are more than 3/4 inch in width are usually made with spiral
or helical teeth. A plain spiral-tooth milling cutter produces a better and smoother
finish and requires less power to operate. A plain helical-tooth milling cutter is
especially desirable when milling an uneven surface or one with holes in it.

Milling cutter nomenclature

FIGURE A.1

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

Types of Teeth

The teeth of milling cutters may be made for right-hand or left-hand rotation, and with either
right-hand or left-hand helix. A right-hand cutter must rotate counterclockwise; a left-hand
cutter must rotate clockwise. The right-hand helix is shown by the flutes leading to the right;
a left-hand helix is shown by the flutes leading to the left. The direction of the helix does not
affect the cutting ability of the cutter, but take care to see that the direction of rotation is
correct for the hand of the cutter.

Left hand cutter Right hand cutter

FIGURE A.2

B. TYPES OF CUTTERS

PLAIN MILLING CUTTER
The most widely used milling cutter which is used to produce flat surface parallel to the
axis. These cutters may be of several types.

 Light duty plain milling cutter
This is used only for light milling operations since it has too many teeth to permit the chip
clearance required for heavier cuts.

FIGURE B.1

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Heavy duty plain milling cutter
These have fewer teeth than the light-duty type, which provides for better chip clearance.
The helix angle varies up to 45 degrees. This greater helix angle on the teeth produces a
smoother surface due to the shearing action and reduces chatter. Less power is required
with this cutter than with straight-tooth and small helix angle cutters.

FIGURE B.2

SIDE MILLING CUTTERS
Side milling cutters are used for milling the sides of a workpiece or for cutting slots or
grooves.

 Plain side-milling cutters

These have straight teeth on the periphery and both sides.
They are used for moderate-duty side milling, slotting, and
straddle milling operations.

FIGURE B.3

 Half-side milling cutters

These have teeth on the periphery and only one side.
They are recommended for heavy-duty side-milling and
straddle-milling operations.

FIGURE B.4

 Staggered-tooth side-milling cutters FIGURE B.5

These are cutters with teeth that alternate to either side.
This tooth arrangement provides more chip clearance and
reduces scoring (grooved marks) on the side surfaces
being machined. Cutters of this type are recommended for
heavy-duty machining of grooves or keyways.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

FACE MILLING CUTTERS

These cutters are generally over 6 in. (150mm) in diameter and
have inserted teeth held in place by a wedging device. This
type of cutter is often used as a combination cutter, making
rough and finishing cut in one pass.

FIGURE B.6

METAL SLITTING SAW

Metal-slitting saws are used for ordinary cutoff operations and for narrow slots. They are
available with several kinds of teeth.

 Plain metal-slitting saws

They have fine teeth and the sides of the teeth taper
toward the hole. The taper prevents the blade from
binding in the slot as it rotates.

 Staggered-tooth metal-slitting saws FIGURE B.7

These are recommended for cuts of 3/16” (4.8mm) and
wider.

 Screw-slotting cutters

These are special fine-tooth plain slitting saws. They are available in widths from 0.020” to
0.182” (0.5 to 4.6 mm)

ANGULAR MILLING CUTTERS

Angular milling cutters are used for machining V-notches, grooves, serrations, dovetails,
and reamer teeth.

 Single-angle cutters

This has a single angle with cutting edges on both
sides of the angle. Generally they are available either
45 or 60 degree angles.

FIGURE B.8

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Double-angle cutters
This has V-shaped teeth. They usually are available
with 45, 60, or 90 degree angles.

FIGURE B.9

FORMED CUTTERS
Contour cutters are used for cutting curved surfaces of regular or irregular shape. They are
used for cutting curved grooves, rounded corners, or flutes in reamers, milling cutters, or
gear teeth.

Concave form cutter Convex form cutter Gear cutter
FIGURE B.10 FIGURE B.11 FIGURE B.12

Corner rounding cutter
FIGURE B.13

 Concave and Convex Milling Cutters

Concave and convex milling cutters are formed tooth cutters shaped to produce concave
and convex contours of 1/2 circle or less. The size of the cutter is specified by the diameter
of the circular form the cutter produces.

 Corner Rounding Milling Cutter

The corner-rounding milling cutter is a formed tooth cutter used for milling rounded corners
on workpieces up to and including one-quarter of a circle. The size of the cutter is specified
by the radius of the circular form the cutter produces, such as concave and convex cutters
generally used for such work as finishing spur gears, spiral gears, and worm wheels.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

END MILLING CUTTERS

These are commonly called end mills. They are designed for milling slots, shoulders,
curved edges, keyways, and pockets where ordinary arbor-type cutters cannot be used.
End mills are of two basic types, solid and shell. In solid mills, the teeth and the shank are
all one piece. While for the shell mills, it has body with cutting edges but no shank.

Two-flute end mill Multiple-flute end mill Ball-end mill
FIGURE B.14 FIGURE B.15 FIGURE B.16

 Two-flute end mills
This is designed with end-cutting teeth for plunge and traverse milling. This kind of end
mill can be fed into the workpiece like a drill. After penetrating the workpiece, it then can
be fed longitudinally.

 Multiple-flute end mills
These have three, four, six or eight flutes depending on their diameter. Only those with
end-cutting teeth may be used for plunge milling to depth as well as for longitudinal
milling.

 Ball-end mills

These are used for milling pockets in dies. They are also used for milling fillets or slots.
Four-fluted ball-end mills are also available ad are used for similar operations.

 SHELL-END MILLS

These are made in larger sizes than shank-type end mills.
Cutters of this type are used for machining larger
shoulders or surfaces. The teeth on all types of milling
cutters stay sharp longer if they have a chamfer or a
radius ground on the corner of the teeth.

FIGURE B.17

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

T SLOT CUTTER FIGURE B.18

The T-slot milling cutter is used to machine T-slot
grooves in worktables, fixtures, and other holding
devices. The cutter has a plain or side milling cutter
mounted to the end of a narrow shank. The throat of
the T-slot is first milled with a side or end milling cutter
and the headspace is then milled with the T-slot milling cutter.

WOODRUFF KEYSLOT MILLING CUTTERS FIGURE B.19

The Woodruff keyslot milling cutter is made in straight,
tapered-shank, and arbor-mounted types. The most
common cutters of this type, under 1 1/2 inches in
diameter, are provided with a shank. They have teeth
on the periphery and slightly concave sides to provide
clearance. These cutters are used for milling semi
cylindrical keyways in shafts.

FLYCUTTER

It is a single-pointed cutting tool with the cutting end ground
to the desired shape. It is mounted in a special adapter or
arbor. Since the cutting is done with the tool, a fine feed must
be used. This cutter is used in experimental work and when
the high cost of a specialty shaped cutter would not be
warranted.

DOVETAIL CUTTER FIGURE B.20
FIGURE B.21
This is a similar to a single-angle milling cutter with in
integral shank. They are used to form the sides of a
dovetail after the tongue or the groove has been
machined with another suitable cutter, usually a side
milling cutter. Dovetail cutters may be obtained with 45,
50, or 60° angles.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

C. CARE AND MAINTENANCE OF MILLING CUTTERS

Milling cutters are expensive and easily damaged if care is not taken in use and storage.
The following recommendations will help extend cutter life:

1. Use sharp cutting tools! Machining with dull tools results in low quality work and it
eventually damages the cutting edges beyond salvage by grinding.

2. Tools must be properly supported and the work held rigidly.
3. Use the correct cutting speed and feed for the material being machined.
4. An ample supply of cutting fluid is essential.
5. Employ the correct cutter for the job.
6. Store cutters in individual compartments.
7. Clean cutters before storing them.

D. CUTTING OILS

The major advantage of using a coolant or cutting oil is that it dissipates heat, giving longer
life to the cutting edges of the teeth. The oil also lubricates the cutter face and flushes away
the chips, consequently reducing the possibility of marring the finish.

 Method of Use

The cutting oil or coolant should be directed by means of coolant drip can, pump system, or
coolant mist mix to the point where the cutter contacts the workpiece. Regardless of
method used, the cutting oil should be allowed to flow freely over the workpiece and cutter.

E. MILLING ATTACHMENTS AND ACCESSORIES

ARBORS, COLLETS, and ADAPTERS

 Arbors
Used for mounting the milling cutter, are inserted and held in the main spindle by a draw
bolt or special quick-change adapter.

Lock nut Spindle Taper Cutter Bearing Bushing

Nut

Arbor Spacers
FIGURE E.1
Draw-in bar

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

THREE STYLES OF ARBORS

 Style A

It has a cylindrical pilot on the end that runs in a bronze bearing in the arbor support. This
style is mostly used on small milling machines or when maximum arbor support clearance
is required.

 Style B

It is characterized by one or more bearing collars that can be positioned to any part of the
arbor. This allows the bearing support to be positioned close to the cutter, to-obtain rigid
setups in heavy duty milling operations).

 Style C

Arbors are used to mount the smaller size milling cutters, such as end mills that cannot be
bolted directly on the spindle nose. Use the shortest arbor possible for the work.

PPiilloott bbeeaarriinngg

SSttyyllee AA SSttyyllee CC

Style B

FIGURE E.2

 Shell-end mill arbors
It may be fitted into the main spindle or the spindle of the vertical attachments. These
devices permit face milling to be done either horizontally or vertically.

 Screw Arbor

Screw arbors are used to hold small cutters that have threaded holes. These arbors have a
taper next to the threaded portion to provide alignment and support for tools that require a
nut to hold them against a taper surface. A right-hand threaded arbor must be used for
right-hand cutters while a left-hand threaded arbor is used to mount left-hand cutters.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Slitting saw arbor

The slitting saw milling cutter arbor is a short arbor having two flanges between which the
milling cutter is secured by tightening a clamping nut. This arbor is used to hold metal
slitting saw milling cutters used for slotting, slitting, and sawing operations.

 Fly cutter arbor

The fly cutter arbor is used to support a single-edge lathe, shaper, or planer cutter bit for
boring and gear cutting operations on the milling machine.

Shell End Screw

Slitting Saw Fly cutter
FIGURE E.3

 Collets

A collet is a form of a sleeve bushing for reducing the size of the hole in the milling machine
spindle so that small shank tools can be fitted into large spindle recesses. They are made in
several forms, similar to drilling machine sockets and sleeves, except that their tapers are
not alike.

FIGURE E.4

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Spindle Adapters
A spindle adapter is a form of a collet having a standardized spindle end. They are
available in a wide variety of sizes to accept cutters that cannot be mounted on arbors.
They are made with either the Morse taper shank or the Brown and Sharpe taper with tang
having a standard spindle end.

FIGURE E.5
 Chuck Adapter
A chuck adapter is used to attach chucks to milling machines having a standard spindle
end. The collet holder is sometimes referred to as a collet chuck. Various forms of chucks
can be fitted to milling machines spindles for holding drills, reamers, and small cutters for
special operations.

FIGURE E.6

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Quick-Change Tooling

The quick-change adapter mounted on the spindle nose is used to speed up tool changing.
Tool changing with this system allows you to set up a number of milling operations such as
drilling, end milling, and boring without changing the setup of the part being machined. The
tool holders are mounted and removed from a master holder mounted to the machine
spindle by means of a clamping ring.

FIGURE E.7

ATTACHMENTS

 Vertical attachment

The vertical milling attachment which may be
mounted on the face of the column or the overarm
enables the horizontal milling machine to be used
for such operations as face milling, end milling,
drilling, boring, and T-slot milling. The spindle
head can be swiveled accurately to any degree for
any angular milling purposes.

FIGURE E.8

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Universal milling attachment

It is a modification of vertical milling attachment
which may be swiveled in two planes, parallel to
the column and at right angles to it. This
attachment permits the efficient use of small and
medium size end mills and cutters for such
operations as die sinking and key seating. This
allows an end mill to do the work of angular
surfaces.

FIGURE E.8

 Compound vertical milling attachment

The spindle can be set in two planes, with the
spindle set at an angle to the table, as in milling
beveled edges to long pieces. The full length of
the table can be traveled, thus saving set-up time.

FIGURE E.9

 Rack milling attachment

Rack milling attachment is used to mill longer gear
racks (rack gears) which generally mesh with
pinion gears.

FIGURE E.10

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 3.2.1: Cutting Tools and Accessories

 Slotting attachment

It converts the rotary motion of the spindle into
reciprocating motion for cutting keyways, splines,
templates, and irregularly shaped surfaces. An angle
can be set between 0 to 90 degrees in either side of the
center line. The stroke can be set from 0 to 4 in.

FIGURE E.11

 Rotary attachment or circular milling

It is bolted to the top of the table, of a plain universal
milling machine. It is used for circular T-slots and cams.

FIGURE E.12

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

Learning outcomes:
4 Setup work piece
Learning Activity:
4.1 Identify the procedure in setting the work piece

A. BASIC MILLING MACHINE SETUPS FOR VERTICAL MILLING MACHINE

ALIGNING THE VISE

When the vise is aligned on a vertical FIGURE A.1
milling machine, the dial indicator may
be attached to the quill or the head by
any convenient means.

In the setting up of the vice onto the
machine table, the fix jaw of the vice
must be set parallel to the machine
table using a Parallel Bar and a Dial
Indicator. Adjustments can only be
made by using a hide face hammer to
correct its position such that a near
zero indicator movement is achieved at
all positions along the parallel bar.

MOUNTING AND REMOVING CUTTERS

The spring collet is pulled into the spindle by a draw-bar that closes on the cutter shank
and drives it by means of friction between the collet and cutter. The solid collet is pulled
into the machine spindle by a draw-bar and is more rigid than spring collet and hold the
cutting securely.

Solid collet Spring collet
FIGURE A.2
FIGURE A.3
Mill Work piece (Basic)
Code No. Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

 To mount a cutter in a spring collet

1. Shut off the electric power to the machine.
2. Clean the taper in the machine spindle.
3. Place the proper cutter, collet, and wrench on a piece of masonite on the table.
4. Place the draw-bar into the hole in the top of the spindle.
5. Insert the collet into the bottom of the spindle, press up, and turn it until the keyway

aligns with the key in the spindle.
6. Hold the collet up with one hand and, with the other, thread the draw-bar clockwise

into the collet for about four turns.
7. Hold the cutting tool with a cloth and insert it into the collet of the full length of the

shank.
8. Tighten the draw-bar into the collet (clockwise) by hand.
9. Hold the spindle brake lever and tighten the draw-bar as tightly as possible with a

wrench, using hand pressure only.

Placing a collet on a piece When tightening the draw bar
of masonite. use hand pressure only.

FIGURE A.4 FIGURE A.5

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

 To mount a cutter in a solid collet

1. Shut off the electric power to the machine.
2. Slide the draw-bar through the top hole in the spindle.
3. Clean the spindle taper and the taper on the collet.
4. Align the keyway or slots of the collet with the keyway or drive keys in the spindle,

and insert the collet into the spindle.
5. Hold the collet up with one hand and, with the other, thread the draw-bar clockwise

into the collet.
6. Pull on the brake lever and tighten the draw-bar as tightly as possible with a wrench,

using hand pressure only.
7. Insert the end mill into the collet until the flat(s) align with the setscrew(s) of the

collet.
8. Tighten the setscrews securely using hand pressure only.

 To remove a cutter from the collets

1. Shut off electric power to the machine.
2. Pull on the spindle brake lever to lock the spindle, and loosen the draw-bar with a

wrench (counter clockwise).
3. Loosen the draw-bar, by hand, only about three full turns.

Note: Do not unscrew the draw-bar from the collet.
4. Hold the cutter with a cloth.
5. Remove the cutter from the collet.
6. Clean the cutter and replace to its proper storage.

B. BASIC MILLING MACHINE SETUPS FOR HORIZONTAL MILLING MACHINE

To prolong the life of milling machine the following actions should be done.

1. Check the surfaces and accessories free from dirt and chips before starting the
machine.

2. Place the tools, parts, and cutters to their proper places.
3. Follow machine procedures and instructions while operating.

 Mounting and removing a milling machine arbor

The milling arbor is used to hold the cutter during the machine operation. Follow the proper
procedures to preserve the accuracy of the machine.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

The arbor assembly

The milling cutter is driven by a key that fits into the keyway on the arbor and cutter. This
prevents the cutter from turning on the arbor. Spacer and bearing bushing holds the cutter
in position on the arbor after the nut as been tightened. The taper end of the arbor is held
securely in t he machine spindle by a draw-in bar. The outer end of the arbor assembly is
supported by the bearing bushing and the arbor support.

Arbor Arbor support

Spindle

Draw-in Arbor nut
bolt
Journal bearing
 To mount an Arbor FIGURE A.5

1. Clean the tapered hole in the spindle and the taper on the arbor using clean cloth.
2. Check the bearing bushing and remove any burrs using a honing stone.
3. Place the tapered end of the arbor in the spindle.
4. Place the right hand on the draw-in bar and turn the thread into the arbor.
5. Tighten the draw-in bar lock nut securely against the back of the spindle.

 To remove an Arbor

1. Remove the milling machine cutter.
2. With a soft-faced hammer, strike the end of the draw-in bar until the arbor taper is

free.
3. Carefully remove the arbor from the tapered spindle.
4. Store the arbor in a suitable rack to prevent damage.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

Mounting and removing milling cutters

Milling cutters must be changed frequently to perform various operations, so it is important
to follow certain sequences to prevent damage.

 To mount a milling cutter

1. Set the machine to the lowest spindle speed.
2. Check the spindle direction.
3. Slide the spacing collars on the arbor to the position desired for the cutter.
4. Fit a key into the arbor keyway at the position where the cutter is to be located.
5. Hold the cutter with a cloth and mount it on the arbor. Make sure that the cutter teeth

point in the direction of the arbor. Slide the arbor support in place and be sure that it
is on a bearing bushing on the arbor.
6. Lock the arbor support in position.
7. Tighten the arbor nut firmly with a wrench.
8. Lubricate the bearing collar in the arbor support.

 To remove a milling cutter

1. Clean all cuttings from the arbor and cutter.
2. Set the machine spindle to the lowest speed.
3. Loosen the arbor nut with a properly fitting wrench.

Note: Most threads on arbors are left-hand; therefore, loosen in a clockwise
direction.

4. Remove the arbor support form the over arm.
5. Place the nuts, spacers, and cutter on a board not on the table surface.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 4.1.1: Procedures in setting the work piece

Setting the cutter to the work surface

The operator should check that the work and the cutter are properly mounted and that the
cutter is revolving in the right direction.

 To set the cutter to the work surface

1. Raise the work under the cutter.
2. Hold a long piece of thin paper and put-in between the cutter and the work.

Note: make sure the paper is long to prevent the finger to touch the cutter.
3. Start the cutter rotating.
4. With the left hand on the elevating screw handle, move the work up slowly until the

cutter grips the paper.
5. Stop the spindle.
6. Move the table away from the cutter.
7. raise the knee of 0.05mm (paper thickness)
8. Then set the graduated collar to zero (0).
9. Raise the table to the desired depth of cut.

Centering a cutter to mill a slot

1. Locate the cutter as close to the center of the work as possible.
2. Using steel square and rule or a gage block, adjusts the work to the center by using

the cross feed screw dial.
3. Lock the saddle to prevent movement during the cut.
4. Move the work clear of the cutter and set the depth of cut.
5. Proceed to cut the slot using the same methods as for milling a flat surface.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

Learning outcomes:
5 Perform milling operations
Learning Activity:
5.1 Calculate formulas for speeds and feeds

A. CUTTING SPEEDS AND FEEDS FOR MILLING

Cutting speed in milling refers to the distance a point on the circumference of the milling
cutter travels in one minute. This is expressed in feet per minute (fpm) of meters per minute
(mpm). You can visualize the cutting speed of a milling cutter by imagining it as the
distance the cutter rolls across the floor during one minute.

Different cutting speeds should be used when machining different metals. If the cutting
speed is too fast, the cutter overheats and dulls rapidly. If the speed is too slow, time is
wasted and production costs will increase.

TABLE 1:

CUTTING SPEEDS FOR MILLING WITH HIGH SPEED STEEL CUTTERS

Material FPM Cutting speed range
Low carbon steel 80-100 MPM
Medium carbon steel 24.4-30.5
annealed
High carbon steel 75-95 22.9-29.0
annealed
Tool steel annealed 60-80 18.3-24.4
Stainless steel 60-80 18.3-24.4
Gray cast iron, soft 60-80 18.3-24.5
Malleable iron 60-81 18.3-24.6
Aluminum and its alloys 80-100 24.4-30.5
Brass 400-1000 122-305
Bronze 20-300 61.0-91.4
100-200 30.5-61.0

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

Revolutions per Minute (rpm)

After the cutting speed to be used has been determined, the machine spindle must be set
at the proper rpm. Cutting speed and rpm have different meanings, and they should not be
confused. A small diameter milling cutter must turn at a higher rpm than a larger diameter
cutter for both to cut at the same cutting speed.

Calculating rpm

The rpm of a given cutting speed for milling and hole-machining operations can be
calculated with the following formulas:

Inch formula Where:
CS (fpm) x 12 CS = Cutting speed
D = Diameter of cutter
RPM = π = Pi or 3.1416
D" x π

Shortcut formula:
4 x CS (fpm)

RPM =
D"

Metric formula:
CS (mpm) x 1000

RPM = D (mm) x π

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

TABLE 2:

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

Example:

Calculate the rpm for 3” (76.2mm) diameter cutter that is to mill steel at 90 fpm (27.43
mpm).

Inch solutions: Metric solution:

A. CS (fpm) x 12 CS (mpm) x 1000
RPM = RPM = D (mm) x π
D" x π

= 90 x 12 = 27.3 x 1000
= 3 x 3.1416 = 76.2 x 3.14
RPM = 1080 RPM = 27430
9.42 239.39
114.6 (compare to table #2) 114.6

B. 4 x CS (fpm)
RPM =
D"

= 90 x 4
= 3
RPM =
360
3

120

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

TABLE 3:

Calculating the Rate of Feed
The following procedure is used for calculating the rate of feed:

1. Determine the desired cutting speed (see in table 1). For example, 100 fpm (30.5
mpm) for low-carbon steel.

2. Determine the rpm of the cutter (see table 2).
3. Count the number of teeth on the cutter.
4. Determine the feed in inches (or mm) per tooth (see table 3).
5. Calculate the feed rate with the formula:

F = R x T x rpm Where:
F = Feed rate in inches (or mm) per minute
R = Feed per tooth per revolution
T = Number of teeth on cutter
Rpm = Revolutions per minute of the cutter

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 5.1.1: Speeds and feeds

Example
Determine the feed rate for milling low-carbon steel at 100 fpm (30.5 mpm) and 127 rpm,
using a heavy-duty plain milling cutter 3” (76.2 mm) in diameter with 10 teeth and a feed of
0.008” (0.20 mm) per tooth.

F = R x T x rpm
F = 0.008 x 10 x 127
F = 10.16 inches (254 mm) per minute

*With the feed-selector dial or levers, adjust the feed rate to the feed closest to 10.16
inches (254 mm) per minute.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Worksheet 5.1.2: Speeds and feeds

Learning outcomes:
5 Perform milling operations
Learning Activity:
5.1 Identify and calculate formulas for speeds and feeds.

PROBLEM SOLVING (10pts each)
Calculate the required spindle speed and feed rate. Solve the following given both in
English and metric. Convert it if necessary.

1. Calculate the rpm for 3” (76.2mm) diameter cutter that is to mill steel at 90 fpm
(27.43 mpm).

2. Calculate the rpm for end mill Ø8 – 3NT cutter that is to mill aluminum material at
250 fpm.

3. Calculate the rpm for end mill Ø12 – 2NT cutter that is to mill cast iron material at
70 fpm.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 6.1.1: Milling safety

Learning outcomes:
6 Perform milling operations
Learning Activity:
6.1 Identify milling safety practices

A. SAFETY RULES FOR MILLING MACHINES

Milling machines require special safety precautions while being used. These are in addition
to those safety precautions described in Chapter 1.

 Do not make contact with the revolving cutter.
 Place a wooden pad or suitable cover over the table surface to protect it from

possible damage.
 Use the buddy system when moving heavy attachments.
 Do not attempt to tighten arbor nuts using machine power.
 When installing or removing milling cutters, always hold them with a rag to prevent

cutting your hands.
 While setting up work, install the cutter last to avoid being cut.
 Never adjust the workpiece or work mounting devices when the machine is

operating.
 Chips should be removed from the workpiece with an appropriate rake and a brush.

FIGURE A.1

Note: Chip rake should be fabricated to the size of the T-slots

 Shut the machine off before making any
adjustments or measurements.

 When using cutting oil, prevent splashing by
using appropriate splash guards. Cutting oil on
the floor can cause a slippery condition that
could result in operator injury

 Emphasis should be given that the eyes of the FIGURE A.2
machine operator must be protected by wearing
a face shield to prevent accident.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

Learning outcomes:
6 Perform milling operations
Learning Activity:
6.2 Identify techniques in basic milling operations

A. METHODS OF MILLING

Milling operations can be classified into one of two distinct methods:

1. With conventional or up-milling, the work is fed INTO the rotation of the cutter; the
chip is at minimum thickness at the start of the cut. The cut is so light that the cutter
has a tendency to slide over the work until sufficient pressure is built up to cause the
teeth to bite into the material. This alternative sliding to start, followed by the sudden
breakthrough as the tooth completes the cut, leaves marks so familiar on many
milled surfaces. The marks and ridges can be kept to minimum by keeping the table
gibs properly adjusted.

2. With climb or down-milling, the work moves in the same direction as cutter
rotation. Full engagement of the tooth is instantaneous. The sliding action of
conventional milling is eliminated, resulting in a better finish and tool life.

The main advantage of climb milling is the tendency of the cutter to press the work down on
the work table or holding device.

Climb milling is NOT recommended on LIGHT MACHINES nor on large OLDER
MACHINES that are NOT in top condition.

Direction of Cutter Rotation

 UP CUT MILLING

In up cut milling, the cutter rotates in a
direction opposite to the table feed as
illustrated in figure 14. It is conventionally used
in most milling operations because the
backlash between the leadscrew and the nut
of the machine table can be eliminated.

FIGURE A.1

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

 DOWN CUT MILLING

In down cut milling, the cutter rotates in the
same direction as the table feed as illustrated
in figure 15. This method is also known as
Climb Milling and can only be used on
machines equipped with a backlash eliminator
or on a CNC milling machine. This method,
when properly treated, will require less power
in feeding the table and give a better surface
finish on the workpiece.

FIGURE A.2
B. BASIC MILLING OPERATIONS USING HORIZONTAL MILLING MACHINE

MILLING A FLAT SURFACE

This is the most common operation done in milling
machine. The work may be held with a vise or
clamped to a table.

Procedure for plain milling cutter:

1. Remove all burrs from all edges of the work

with a file.

2. Align the vise to the column face of the milling

machine using a dial indicator. FIGURE B.1

3. Set the work in the vise using parallels and paper feelers under each corner to make

sure that the work is seated on the parallels.

4. Tighten the vise securely by hand. Do not use a hammer on the vise wrench.

5. Tap with a soft-faced hammer the four corners of the work to touch the parallel under

it.

6. Select a helical cutter wider than the work to be machined.

7. Mount the cutter on the arbor for conventional milling.

8. Set the right speed for the size of cutter and the type of work material.

9. Start the cutter and raise the work until it touches the paper feeler.

10. Stop the cutter if it cuts the paper.

11. Move the table away from the cutter.

12. Raise the knee of 0.05mm (paper thickness)

13. Then set the graduated collar to zero (0).

14. Raise the table to the desired depth of cut.

15. Cut first side and the remaining sides.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

FACE MILLING

This process produces a flat vertical surface at right
angles to the cutter axis. Cutters in this operation
are generally inserted-tooth cutters or shell end
mills.

 Procedure for face milling: FIGURE B.2

1. When face milling a large surface, use an inserted-tooth cutter and mount to the
spindle of the machine.

2. When milling smaller surfaces, cutters should be about .25 mm larger than the width
of the workpiece.

3. Set the feeds and speeds.
4. Set up the work on the milling machine making sure that the work-holding clamps do

not interfere with the cutting action.
5. Use cutting fluids if the cutter material or work will allow.
6. Make a rough cut to bring near the finishing size.
7. Set the depth of the finish cut and machine the surface to size.
8. After completing the operation, clean and store cutter and tools to their proper

storage.

SIDE MILING

Side milling is often used to machine a vertical
surface on the sides or the ends of a work piece.

 Procedure for side milling:

FIGURE B.3

1. Set up the work in the vise and on parallels.
2. Tighten the vise securely by hand. Do not use hammer on the vise wrench.
3. Tap the four corners wit ha soft-faced hammer until the paper feelers are tight

between the work and the parallels.
4. Mount a side milling cutter as close to the spindle bearing as possible to provide

maximum rigidity when milling.
5. Set the proper speed and fed for the cutter being used.
6. Start the machine and move the table until the top corner of the work touches the

revolving cutter. Make sure that the cutter is rotation in its proper direction.
7. Set the crossfeed graduated to zero (0).
8. Move the work clear of the cutter.
9. Set the required depth of cut with the crossfeed handle.
10. Lock the saddle to prevent movement during operation.
11. Take the cut across the surface.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

STRADDLE MILLING

In straddle milling, a group of spacers is
mounted in between two side and face
milling cutters on the spindle arbor for the
milling of two surfaces parallel to each
other at a given distance.

 Procedure for straddle milling: FIGURE B.4

1. Select two sharp side milling cutters.
2. Mount the cutters, with suitable arbor spacers, as close to the column as the work

will permit.
3. Mount the arbor support as close to the cutters as possible to provide rigidity for the

cutters and arbor.
4. Center the cutter on the work piece in the proper location.
5. Tighten the saddle lock to prevent any movement during cut.
6. Set the cutter to the work surface.
7. Move the table to clear the end of the work piece.
8. Set the depth of the cut required and tighten the knee clamp.
9. Set the proper speed and feeds for the cutter size and the type of work material,

check cutter rotation.
10. Use a good supply of cutting fluid and complete the straddle operation in one cut.

GANG MILLING

Gang milling is a horizontal milling operation that
utilizes three or more milling cutters grouped
together for the milling of a complex surface in
one pass. Different type and size of cutters
should be selected for achieving the desire
profile on the work piece.

FIGURE B.5

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

 Procedure for gang milling:

1. Select cutters that are as close as possible to the same size and the same number
of teeth. This will allow maximum speeds and feeds to be used.

2. Mount the correct cutters on the arbor as close to the machine column as possible.
3. Fasten the arbor support as close as to the cutters as the work will permit.
4. Set the spindle speed to suit the largest-diameter cutter.
5. Be sure that the work is fastened securely and that the workholding devices will not

come in contact with the cutters.
6. Use a good flow of cutting fluid to assist the cutting action and produce a good

surface finish.

SAWING AND PARTING FIGURE B.6

Metal slitting saw milling cutters are used to
part stock on a milling machine. The work
piece is being fed against the rotation of the
cutter. For greater rigidity while parting thin
material such as sheet metal, the work piece
may be clamped directly to the table with the
line of cut over one of the table T-slots. In
this case, the work piece should be fed with
the rotation of the milling cutter (climb milling)
to prevent it from being raised off the table.

Every precaution should be taken to
eliminate backlash and spring in order to
prevent climbing or gouging the work piece.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations Concave Cutter

FORM MILLING Corner Rounding
Cutter
Form milling is the process of machining special contours
composed of curves and straight lines, or entirely of
curves, at a single cut. This is done with formed milling
cutters, shaped to the contour to be cut.

The more common form milling operations involve milling
half-round recesses and beads and quarter-round radii on
work pieces. This operation is accomplished by using
convex, concave, and corner rounding milling cutters
ground to the desired circle diameter.

Convex Cutter
FIGURE B.7

C. BASIC MILLING OPERATIONS USING VERTICAL MILLING MACHINE

MACHINING A FLAT SURFACE

 Procedure for milling flat surface

1. Clean the vise and mount the work

securely in the vise, on parallels if

necessary.

2. Check the vertical head if square with

the table.

3. Select a cutter which overlaps to the

edges of the work to machine in just

one cut. FIGURE C.1

4. See the proper spindle speed for the size and type of cutter and the material being

machined; check cutter rotation.

5. Tighten the quill clamps.

6. Star the machine, and adjust the table until the end of the work is under the edge of

the cutter.

7. Raise the table until the work surface just touches the cuter. Move the work clear of

the cutter.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

8. Take a trial cut for approximately 5mm.
9. Move the work clear of the cutter, stop the cutter, and measure the work.
10. Then raise the table the desired amount, and lock the knee clamp.
11. Mill the surface of the work.

MACHINING A BLOCK SQUARE AND PARALLEL

In order to mill the four sides of a piece of work to make it square and parallel, it is
important that each side must be machined in a definite order. Remove dirt and burrs that
can cause inaccuracy.

 Machining side 1

1. Clean the vise and remove all burrs from

the workpiece.

2. Set the work on parallels in the center of the

vise with the largest surface (side 1) facing

up.

3. Place short paper feelers under each corner

between the parallels and the work. FIGURE C.2
4. Tighten the vise securely.

5. With a soft-faced hammer, tap the workpiece down until all paper feelers are tight.

6. Mount a flycutter in the milling machine spindle.

7. Set the machine fro the proper speed for the size of the cutter and the material to be

machined.

8. Start the machine and raise the table just touches near the right-hand end of side 1.

9. Move work clears of the cutter the cutter.

10. Raise the table and machine side 1 using steady feed rate.

11. Take the work out of the vise and remove al burrs from the edges with a file.

 Machining side 2

12. Clean the vise, work, a parallels thoroughly.

13. Place the work on parallels, if necessary,

with side 1 against the solid jaw and side 2

up.

14. Place short paper feelers under each corner

between the parallels the work.

15. Place a round bar between side 4 and the FIGURE C.3
movable jaw.

Note: the round bar must be in the center of the amount of work held inside the vise

jaws.

16. Tighten the vise securely and tap the work down until the paper feelers are tight.
17. Follow steps 8 t0 11 and machine side 2.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

 Machining side 3

18. Place side 1 against the solid vise jaw, FIGURE C.4
with side 2 resting on parallels if
necessary. Place a round bar between
side 4 and the movable jaw, making sure
that the round bar is in the center of the
amount of work held inside the vise.

19. Tighten the vise and tap the work.
20. Start the machine until the cutter touches near the

right-hand end of side 3.
21. Take a trial cut of about 6mm long, stop

the machine, and measure the width of
the work.
22. Raise the table the required amount and
machine side 3 to correct width.

 Machining side 4

23. Place side 1 down on the parallels with FIGURE C.5
side 4 up and tighten the vise securely.

24. Tighten the vise securely. Tap the work.
25. Follow steps 24 to 27 and machine side 4

to the correct thickness.

MACHINING THE END SQUARE

 Procedure for short work:

1. Set the work in the center of the vise with FIGURE C.6
one of the ends up and tighten the vise lightly. FIGURE C.7

2. Hold a square down firmly on top of the vise jaws
and bring the blade into light contact with
the side of the work.

3. Tap the work until its edge is aligned with
the blade of the square.

4. Tighten the vise and recheck the
squareness of the side.

5. Cut about 1mm deep and machine the end
square.

6. Remove the burrs from the end of the
machined surface.

7. Tighten the vise and tap the work down on the vise.
8. Take a trial cut until the surface cleans up.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

9. Measure the length of the workpiece with a depth
micrometer.

10. Raise the table the required amount and machine
the work to length.

MACHINING ANGULAR SURFACES

FIGURE C.8

Angles may sometimes be milled by leaving the head in a vertical position and setting the
work on an angle in the vise. This will depend on the shape and size of the workpiece.

 To Machine an Angular Surface

1. Check he vertical head is square with the table.
2. Clean the vise.
3. Lock the quill clamp.
4. Set the workpiece in the vise with the layout line

parallel to the top f the ivies jaws and about ¼ in.
(6 mm) above them.
5. Adjust the work under the cutter so that the cut
will start at the narrow side of the taper and
progress into the thicker metal.
6. Take successive cuts of about .125 in to .150 in.
(3 to 4 mm), or until the cut is about 1/32 in. (0.8
mm) above the layout line.
7. Check to see that the cut and the layout line are
parallel.
8. Raise the table until the cutter just touches the
layout line.
9. Clamp the knee at this setting.
10. Take the finishing cut.

FIGURE C.9

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

DRILLING ANGULAR HOLES

Angular holes may be drilled on a vertical mill by swiveling the head to the required angle
and feeding the drill into the workpiece by using the quill handfeed lever.

 To Drill Angular Holes

1. Mount the work in the vise, or clamp it to

the machine table.

2. Loosen the lock nuts and swivel the milling

head to the required angle of the hole to be

drilled.

3. Check the angle of the head by the

graduations on the housing, or with a bevel

or vernier protractor.

4. Tighten the lock nuts and recheck the

accuracy of the setting. FIGURE C.10
5. Mount a drill chuck in the spindle.

6. Mount a center finder in the drill chuck.

7. Locate the center of the spindle as close as possible to where the hole is to be

drilled.

8. Lower the table so that there is enough room between the spindle in the up position

and the top of the work to mount longest drill bit required for the drilling operation.

9. Lock the knee of the machine in this position and do not move it; otherwise, the hole

location will be lost.

10. Adjust the table until the center punch mark of the hold to be drilled is in line with the

tip of the rotating center finder.

11. Tighten the table and saddle clamps.

12. Stop the machine, raise the spindle to the top position with the quill handfeed lever,

and remove the center finder.

13. Insert a large center drill or spotting tool into the drill chuck.

14. Set the spindle speed for the size of spotting tool to be used.

15. Spot each hole location so that the top of spotted hole is slightly larger than the size

of hole to be drilled.

a) This is necessary so that the edge of the drill is not deflected when drilling on an

angle.

b) To prevent any possible deflection, use an end mill (size of drill diameter) to

counter bore the top of each hole until it reaches its full diameter.

16. When one more than angular hole must be drilled, it is wise to record the crossfeed

and table micrometer collar locations of each hole.

17. Stop the machine and remove spotting tool.

18. Insert the correct size drill into the drill chuck.

19. Set the speed and feed for each hole to be drilled.

20. Drill each hole to the required depth.

21. Remove all burrs from the hole edges with a file and scraper.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

REAMING ON A VERTICAL MILL

The purpose of reaming is to bring a drilled or bored hole to size and shape, and to produce
a good surface finish in the hole. Speed, feed, and reaming allowances are three factors
that can affect the accuracy of reamed hole. The speed of reaming is generally about one-
half of the drilling speed.

Reamer

Vise

FIGURE C.11

 To Ream on a Vertical Mill

1. Mount the reamer on the spindle or drill chuck.
2. Set the speed and fed for reaming (approximately one-quarter the drilling speed).

Too high a speed will quickly dull the reamer.
3. Apply cutting fluid as the reamer is fed steadily into the hole with the down feed

lever.
4. Stop the machine spindle.
5. Remove the reamer from the hole.

Note: Do not turn the reamer backward; otherwise, the cutting edges will ruin.

BORING ON A VERTICAL MILL

Boring is the operation of enlarging and truing a
drilled or cored hole with a single-point cutting
tool. Many holes are bored on a milling machine
to bring them to accurate size and location. The
offset boring chuck is especially useful because
it allows accurate setting to be made for
removing material from a hole.

FIGURE C.12

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

 To Bore in a Vertical Mill

1. Align the vertical head square (at 90) to the table.
2. Set up and align the work parallel to the table travel.
3. Align the center of the milling machine spindle with the reference point or edges of

the work.
4. Set the graduated micrometer dials on the crossfeed and table screws to zero.
5. Calculate the coordinate location for the hole to be bored.
6. Move the table so that the center of the spindle aligns with the hole location required.
7. Lock all table clamps to keep the table in this position.
8. Spot the hole with a center drill or spotting tool.
9. Drill holes under ½ in. (12.7 mm) diameter to within 1/64 in. (0.39 mm) of finish size.

Drill holes over ½ in. (12.7 mm) diameter to within 1/32 in. (0.8 mm) of size.
10. Mount the boring chuck using the largest boring bar or tool possible.
11. Rough bore the hole to within .005 to .007 in. (0.12 to 0.17 mm) of finish size.
12. Finish boring the hole to the required size.

TAPPING HOLES ON A VERTICAL MILL

Tapping a hole on the vertical mill can be
performed either by and or with the use of a
tapping attachment. The advantage of tapping
a hole on a vertical mill is that the tap can be
started squarely and kept that away throughout
the entire length of the hole being threaded.

 To Tap on a Vertical Mill FIGURE C.13

1. Mount the work in a vise, or clamp it to the machine table. If parallels are used in the
work setup, be sure that they clear the hole to be tapped.

2. Mount a center drill in the drill chuck, and adjust the machine table until the center
punch mark on the work aligns with the point of center drill.

3. When a center drill spot each hole to be tapped to slightly larger than the tap
diameter.

4. Drill the hole to the correct tap drill size for the size of tap to be used.

Note: the work or table must not be moved after drilling the hole; otherwise, the
alignment will be disturbed and tap will not enter squarely.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Operation Sheet 6.2.1: Basic Milling Operations

5. Mount a stub center in the drill chuck. FIGURE C.14
6. Fasten a tap wrench on the correct size tap

and place it into the hole.
7. Lower the spindle using the quill handfeed

lever until the stub center point fits into the
center hole in the end of the tap shank.
8. Turn the tap wrench clockwise to start the tap
into the hole. At the same time, keep the stub
center in light contact with the tap by applying
pressure on the handfeed lever.
9. Continue to the tap hole while keeping the
tap aligned by applying light pressure on the
handfeed lever.

MILLING WOODRUFF KEYSLOT

The milling of a Woodruff keyslot is relatively simple since the proper sized cutter has the
same diameter and thickness as the key. With the milling cutter located over the position in
which the keyway is to be cut, the work piece should be moved up into the cutter until you
obtain the desired key seat depth. The work may be held in a vise, chuck, between centers,
or clamped to the milling machine table. Depending on its size, the cutter is held in an arbor
or in a spring collet or drill chuck that has been mounted in the spindle of the milling
machine.

Milling woodruff keyslot T slot milling
FIGURE C.15 FIGURE C.16

T-SLOT MILLING

Cutting T-slots in a work piece holding device is a typical milling operation. The size of the
T-slots depends upon the size of the T-slot bolts which will be used. Dimensions of T-slots
and T-slot bolts are standardized for specific bolt diameters.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 7.1.1: Precision measuring instruments

Learning outcomes:
7 Check/ measure work piece
Learning Activity:
7.1 Identify techniques in checking/ measurements in conformance to specifications.

A. THE RULER
A ruler used to be called a rule, and rulers would be rules. Today, the more commonly
found term is ruler. The dictionary defines both the term rule and ruler, so either can be
used, and for this document I will only use the term ruler.

Metric-Rulers
Metric rulers are fairly easy to read. They deal with centimeters and millimeters only. You
won’t have to worry much about fractions

FIGURE A.1
The larger lines with numbers are centimeters, and the smallest lines are millimeters. Since
millimeters are 1/10th of a centimeter, if you measure 7 marks after a centimeter, it is 1.7
centimeters long.

English-Rulers

The unit of length in the inch system is the inch, which may be divided into fractional or
decimal fraction division. The fractional system is based on the binary system or base 2.
The binary fractions commonly used in this system are ½, ¼, 1/8, 1/16, 1/32 and 1/64. The
decimal fraction system has base 10, s any number may be written as a product of ten.

FIGURE A.2 FIGURE A.3

Taking Measurement Using a Steel Rule

 The rule is placed directly across the
length to be measured or is parallel with
respect to such length and vertical to its
edges

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 7.1.1: Precision measuring instruments

 Wherever possible placed against a shoulder

 And that the observer views straight and
vertical on to that place where the
measurement has to be taken.

FIGURE A.4

DIFFERENT TYPES OF GRADUATED TOOLS

Graduated tools are used for measuring length and for marking out. With careful handling,
dimensions to an accuracy of 0.5 mm can be measured, depending upon the instrument
used.

Steel Rules

Steel rules are the most commonly used measuring tools in the shop where high precision
is not required. Different kinds of steel rules are shown in the following figures.

Workshop Rules
FIGURE A.5

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010

Information Sheet 7.1.1: Precision measuring instruments

Folding Ruler
FIGURE A.6

B. VERNIER CALIPER

The Vernier Caliper and all instruments applying its principle carry the name of Pierre
Vernier, a French mathematician who invented it in 1631. Basically, the Vernier Caliper is
an igneous development of the ordinary steel rule, be it in inches, where the Vernier
principle is added, to divide finer every graduation on the steel rule. Notice on the figure that
the main scale of the Vernier.

PARTS VERNIER CALIPER

FIGURE B.1

 Fixed Jaws
Fixed jaws are parts of the beam scale. One jaw is used for taking external measurements
and the other for internal measurements.

Code No. Mill Work piece (Basic) Date: Developed Date: Revised Page #
ALT723307 May 12, 2010 June 12, 2010