Milling Workpiece (Intermediate)

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Learning outcomes:
1 Determine job requirement
Learning Activity:
1.1 Select cutting tools

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 1

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Milling cutters are cutting tools used on a milling machine. Some of the milling cutters
used in the milling shop are:

 Plain milling cutters
 Side milling cutters
 Angular milling cutters
 Formed cutters
 End milling cutters
 Face milling cutters

 They are usually made of high-speed steel.
 They have cutting teeth on the periphery only.
 They are usually mounted on the horizontal milling machine arbor.
 They are used for milling plain flat surface

 They are used for light
milling operations only.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 2

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They have straight teeth or
helical teeth

 They have lesser teeth than
the light-duty types to
provide better chip
clearance.

 They have greater helix
angles on the teeth than the
light-duty types.

 They are also called slab
mills

 They have much larger
helix angles on the teeth.

 They have fewer and
coarser teeth than the
other plain milling cutters.

 Generally, they are used
for milling wide and
interrupted surfaces

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 3

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are generally made of high-
speed steel.

 They are usually mounted on the
horizontal milling machine arbor.

 They have cutting teeth on the
periphery and also on one or both
sides of the cutter.

 They have straight teeth on
the periphery and on both
sides of the cutter

 Generally, they are used for
milling slots, steps and
straddle milling.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 4

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 Generally, they are used for
milling slots, steps and
straddle milling.

 They have helical teeth on the
periphery and on one side of the
cutter

 Generally, they are used for
side milling and straddle
milling.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 5

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They have alternating left
and right helical teeth on
the periphery.

 The tooth arrangement
gives a better cutting
action.

 They can be used for
heavier cuts.

 They are generally made of
high-speed steel.

 They are mounted on the
horizontal milling machine
arbor.

 They have cutting teeth that
are not parallel to the cutter
axis.

 They have teeth on one
angular surface and on one
side.

 The angle between the
angular surface and the
side describes the cutter,
e.g. 45˚ or 60˚ angular
cutters.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 6

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are used to mill
angular surfaces e.g.
dovetails.

 They have cutting teeth on
2 angular surfaces.

 Cutters having equal angles
on both faces (symmetrical)
are classified by the size of
the included angle.

Example:
45˚ or 90˚ double-angle

cutters.

 Cutters having unequal
angles on both faces
(unsymmetrical) are
classified by the size of the
angle on each side

Example:
12˚ - 45˚ double-angle

cutter

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are used to mill V-
grooves.

 They are generally made of
high-speed steel.

 Generally, they are made in
standard shapes and sizes.

 They are used for milling
surfaces with a curved
outline

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 9

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are generally made of
high-speed steel and
cemented carbide.

 They have cutting teeth on
the end and the periphery
of the cutter.

 They are generally mounted
on the vertical milling
machines using adaptors.

The shank and the cutter Straight Shank
Threaded shank
are in one piece (integral) Tapered shank
They have different types
of shanks.

 Straight shank
 Threaded shank
 Tapered shank.

 The cutter and shank are
separate.

 They are larger than end
mills.

 Their uses are similar to
that of end mills

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 11

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 12

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 13

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 14

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 Generally, they are made
with 2 flutes.

 They have 2 cutting lips of
different lengths at the end.

 One lip passes the axis of
the cutter.

 The cutters can be fed into
the work like a drill.

 They are generally used to
mill slots that do not extend
to the edge of the
workpiece

 They are made of high-
speed steel.

 They are similar to side
milling cutters except that
they have an integral
shank.

 They are mounted on the
milling machine in the same
way as end mills

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 15

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are made of high-
speed steel.

 They are similar to single-
angle milling cutters except
that they have an integral
shank.

 They have teeth made in
angles of 45˚, 50˚, 55˚ or
60˚

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 16

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are made of high- Single Point Tool
speed steel.
Gear Tooth
 They are single-point tools
ground to the desired
shapes.

 They are mounted in
special adaptors or arbors.

 They are generally used
when formed cutters are
not available

 They are made of high-
speed steel.

 They have integral shanks

 They are used for milling
key seats for woodruff key.

 They are generally made of
high-speed steel.

 They are mounted on
horizontal milling machine

 They are used at lower
feeds than other cutters.

 They are used for the
following milling operations:

 Cutoff operations

 Milling of narrow
slots

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 They are similar to thin
plain milling cutters.

 The sides are tapered
slightly towards the bore to
prevent rubbing on the work

 They have more teeth than
plain milling cutters

 They are Similar to side
milling cutters.

 They are used for deeper
slotting and cutoff
operations.

 They have more teeth than
the side milling cutters.

 They are similar to
staggered-tooth side milling
cutters.

 They are used for deeper
cuts with normal feeds.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 18

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 Do not use a key when
mounting slitting saws on
the arbor.

 This will allow the saw to
slip if it jams in the
workpiece.

 They are shell end mills
with a diameter larger that
150 mm.

 The body is generally made
of tool steel.

 The cutting teeth are made
of high-speed steel or
cemented carbide.

 They are used for milling
large surfaces.

Advantages of cutters having

helical teeth:
 The helical teeth cut with a
shearing action
 Less power is required in
the cutting operations.
 They cut with less chatter.
 They produce good surface
finished on the workpieces.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 19

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Disadvantage of cutters
having helical teeth

 They set up end thrust
which may damage the
spindle bearings.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 20

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 21

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 22

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

The machine table has
to be aligned when machining
side surfaces parallel to the

column.c

Mount the angle plate on the 0 Angle
Plate
machine table Zero
Position Tenons
 Clean the T-slots.

 Place 4 tenons into a T-slot
at a suitable distance from
each other.

 Clamp 2 angle plates on
the machine table using
tenons for alignment.

 Make sure that the dial
indicator can register
readings on the angle
plates.

 Check that the table is set
to zero position.

Dial Indicator Column
G-clamp
Mount a dial indicator on Arbor
Angle Plate
the arbor.
 Use a G-clamp to hold the Table
dial indicator on the arbor.
 Disengage the spindle
gears to allow free
movement of the spindle.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Compare the dial Stylus

indicator readings.
 Use the cross-slide to
enable the stylus of the dial
indicator to locate one of
the angle plates.

Adjust the machine table. Clamping Bolt

 Compare the dial indicator
readings on the 2 angle
plates.

 Use a soft hammer to tap
the machine table in the
correct direction until the
dial indicator has the same
readings on both the angle
plates.

 Tighten the nuts.

 Make sure that the machine is switched off
before making any adjustment.

 Hold the stylus of the dial indicator clear of
the angle plate before tapping the machine
table.

 Make sure that the correct-sized spanner is
used for tightening or loosening the nuts.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Dividing Head Plunger Swivel
 Direct index plate Block
 Swivel block
 Sector arm Index Direct Index Plate
 Index plate Crank
 Index crank
 Plunger Footstock

Footstock Sector Centre
It is used with the dividing Arm Rest

head to support the work- Index Plate
pieces held between centres
Centre Rest
It is used to support long and
slender workpiece.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 25

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

The spindle is attached Worm Wheel (40-teeth)
to a 40-tooth worm wheel
The worm wheel meshes Worm Index Plate
with a worm Shaft Plunger

e or s a 90 to Spindle Worm
the spindle Axis
The worm is connected to
the index crank. Index
The index crank has a Crank
plunger which fits the
holes of the index plate.

Plunger Direct Index
Plate

A direct index plate is Centre
attached to the front of
the spindle

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Direct Index
Plate

A centre or a chuck is Chuck
attached on the end of
the spindle.

Some of the methods of
indexing are:
A Direct Indexing

B Simple Indexing
C Angular Indexing

 Direct indexing is used for Plunger Direct Index
quick indexing of the Plate
workpiece.

 The worm shaft must be
disengaged with the worm
wheel.

 A direct index plate is used.
The plate has slots on both
sides which are equally
spaced.

 The common plate has 24
slots on one side and 30
slots on the other side

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 27

Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

The number of divisions that
can be indexed are numbers
which are factors of 24 and 30.
Example:
To index 8 sides on the
workpiec by direct indexing.
The 24-slot plate can be used
because it is divisible by 8.
Indexing = 24 / 8

= 3 or 3 holes on a 24
slot plate

The number of divisions that 8th Cut 1st Cut
can be indexed are numbers 7th Cut
which are factors of 24 & 30. 2nd Cut
6th Cut 3rd Cut
Example:
To index 8 sides on the 4th Cut
workpiece by direct indexing
The 24-slot plate can be used 5th Cut
because it is divisible by 8.
Indexing = 24/8

= 3 or 3 holes on a 24-
slot plate.

24-slot plate

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

 The index crank, index Worm Wheel
plate and the sector arms (40 Teeth)
are used to index the
workpiece Spindle Workpiece
1/40 Turn One Turn
 The worm must be
engaged with the worm Worm
wheel.

 The worm wheel has 40
teeth.

 One complete turn of the
index crank will rotate the
spindle and the
workpiece 1/40 of a turn.

One complete Turn One complete
Turn
When the index crank
makes 40 complete Workpiece
turns, the spindle and
the workpiece will rotate 40 Complete
one complete turn Turn

The ratio of turns
between the index crank
and the dividing head
spindle is 40:1.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Formula :
Indexing = 40/N
N = No of sides to be indexed.
Example 1
What is the simple indexing for 10 sides?
Working:
Indexing = 40/N

= 40/10
=4
4 turns of the index crank.

The index plate has a few Hole Side Index
circle of equally-spaced Circle Plate
holes
The Brown and Sharpe Sector
plates has a set of 3 index Arms
plates
There is only one Cincinnati INDEX PLATE HOLE CIRCLE
plate with holes on both
sides. BROWN AND SHARPE
In simple indexing, the index
pin engages any one of the Plate 1 15 – 16 – 17 – 18 – 19 – 20
holes on the index plate. Plate 2 21 – 23 – 27 – 29 – 31 - 33
The sector arms are used to Plate 3 37 – 39 – 41 – 43 – 47 - 49
set a fraction of a complete
turn.

CINCINNATI STANDARD PLATE

One Side 24-25-28-30-34-37-38-39-41-42-43
Plate 2 46-47-49-51-53-54-57-58-59-62-66

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Example:
What is the simple indexing for 9 sides?
(Use Brown and Sharpe dividing head.)
Working:
Indexing = 40/9

= 4 4/9
= 4 8/18
Selecting the 18-hole circle,
Index 4 complete turns and 8 holes on a
18-hole circle.
(Use the sector arms to set the 8 holes
on the 18-hole
circle.)

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Formula:
Indexing = No of degrees / 9
One complete turn of the index
crank rotates the work 1/40 turn or
1 40 of 60 c s equal o 9˚

Example 1
Calculate the angular
ndex ng for 6˚.
Working:
Indexing in degrees
= No of degrees 9˚
= 36/9
=4

Calcula e e ndex ng for 50˚,
using
the Brown and Sharpe dividing
head.

Working:
Indexing in degrees
= No of degrees 9˚
= 50/9
= 5 5/9
=5 15/27
Selecting the 27-hole circle, i.e. 5

complete turns and 15 holes on
27-hole
Circle.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Calculate the angular indexing for 45 .
(Use the Brown and Sharpe dividing
head.)
Working:
Indexing in degrees
= No of degrees 9˚
= 45˚ 9˚
= 5 complete turn

Calcula e e angular ndex ng for 60 .
(Use the
Brown and Sharpe dividing head.)
Working:
Indexing in degrees
= No of degrees 9˚
= 60˚ 9˚
= 6 6/9
= 6 12/18
Selecting the 18-hole circle, ie 6
complete turns
and 12 holes on 18-hole Circle.

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
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Information Sheet 3.1.1 : Milling Workpiece ( Intermediate )

Code No. Milling Workpiece ( Intermediate ) Date: Developed Date: Revised Page #
June 10 2010 34

Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )

Learning outcomes:
1 Determine job requirement
Learning Activity:
1.1 Interpreting drawing

1. INTERPRETING DRAWING ( THEORY )

LINES, ORTHOGRAPHIC PROJECTION, SECTIONS, DIMENSIONING SYSTEM, THREADS,SURFACE
CONDITION SYMBOLS, TOLERANCE SPECIFICATION ( THEORY )

1. IDENTIFYING ALPHABETS OF LINES AND THEIR USES

1.1 Classification of lines

Type of line Examples of application Thickness for size

Continuous thick A1 Visible outlines A
0.5 mm
A2 Visible edges 0.7 mm
B
Continuous thin B1 Imaginary lines of intersection

(Straight or curved) B2 Dimension lines

B3 Projection lines

B4 Leader lines

B5 Hatching

B6 Outlines of resolved section place

B7 Short of center line -0.25 0.35
C 0.35
Continuous thin freehand C1 Limit of partial or interrupted views
and section, if the limit is not an D
Continuous thin (straight) axis 0.25
with zigzags
D1 Line (see figure 3 & 4)

Dashed thick E1 hidden outlines E
Dashed thin E2 Hidden edges
F1 Hidden outlines 0.5 0.7
F2 Hidden edges
F --------- ----------
0.25 0.35

Chain thin, thick at ends H1 Cutting planes H - --- - - -
and changes of direction
0.5/0.25 0.7/0.35

Chain thick J1 Indication of lines or surface to which a J ......

special requirement applies 0.5 0.7

Chain thin double-dashed K1 Outline of adjacent parts K -- -- -- -- -- --

K2 Alternative and extreme positions of
movable parts

K3 Centroidal lines
K4 Initial outlines prior to forming (see fig. 1 – 5) 0.5 0.35
K5 Parts situated in front of cutting plane

Code No. Mill Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
1.2 Application of alphabets of lines (Fig.1)

Fig. 1
2. DETERMING ORTHOGRAPHIC PROJECTION
2.1 First Angle Projection (European Method)

In first angle projection, the view is projected on the opposite side from where it was viewed. So
if you view it from the left side you project it on the right side. (Fig. 2 a-c)

Code No. Mill Workpiece Fig. 2a Date: Revised Page #
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Date: Developed
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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )

Fig. 2b

Fig. 2c
2.2 Third Angle Projection (American Method)

In third angle projection, the view is projected on the same side it was viewed. So if you view it
from the top then you project it on the top. (Fig. 3 a-c)

Fig. 3a

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )

Fig. 3b

Fig. 3c

3. ANALYZING SECTIONS
3.1 Presentation of Internal View
3.1.1 If a presentation of internal view contain hidden lines, it is customary to show it in section.
(Fig. 4)

Front view

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )

Fig. 4

3.2 Representation of Cutting Plane
3.2.1 The symbolic line that is used to represent the cutting plane is a long chain line, thick at ends and thin
elsewhere.
The arrowheads at the ends are used to indicate the direction in which the imaginary cut surface is
viewed. Reference letters are added to identify the cutting plane. (Fig. 5)

Fig. 5

3.2.2 The change in direction of the cutting plane, in the case of offset section, may be shown by dash lines.
When the planes passes along the main axis, the symbolic representation of the cutting plane may be
omitted. (Fig. 6)

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
Fig. 6

3.3 Hatching Lines
3.3.1
Hatching is used to make sections evident. It is executed at a well defined angle, preferably 45 degrees
along the axis to the main outline of the section. (Fig. 7)

3.3.2 Fig. 7

Separated areas of a section of a single component are hatched in an identical manner. The hatching of
adjacent components should be carried out at different angles. (Fig. 8)

3.3.3 Fig. 8

Space between the hatching lines should be chosen in proportion to the size of the handed section. In
case of large areas, the hatching may be limited to a zone following the contour of the hatched are.

(Fig. 9)

3.3.4 Fig. 9

Where section of the same part in parallel planes are shown side by side. The hatching lines
should be similar spaced, but offset along the dividing line between the sections. (Fig. 10)

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
Fig. 10

3.3.5 Thin Sections

Thin sections may be shown entirely black. A thin space is left between adjacent sections of this
type. (Fig. 11)

Fig. 11

3.4 Identifying Cutting Planes
3.4.1 Section in One Plane (Fig. 12)

Fig. 12
3.4.2 Section in Two Parallel Planes (Fig. 13)

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
Fig. 13

3.4.3 Section in Three Continuous Planes (Fig. 14)

Fig. 14
3.4.4 Section in two intersecting planes, one shown revolved into the plane of projection. (Fig.15)

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
Fig. 15

3.5 Indentifying Types of Section
3.5.1 Full Section
If the plane cuts entirely across the object, the section represented is known as full section.
(Fig. 16)

3.5.2 Fig. 16
Half Sections
Symmetrical parts may be drawn half in outside view and half in section. (Fig. 17 a-b)

Fig. 17a

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )

Fig. 17b

3.5.3 Revolved or Removed Sections
Cross sections may be revolved in place or removed. In the first case the outline is

shown in continuous thin lines, further identification is not necessary. (Fig. 18)

3.5.4 Fig. 18
Partial Section
If only one part of an object is to be shown then we use partial section. (Fig. 19)

Code No. Mill Workpiece Fig. 19 Date: Revised Page #
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Date: Developed
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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
3.5.5 Assembly Section
To show the relationship of parts if assembled, assembly section is used. 9Fig. 20)

Fig. 20
3.6 Parts that do not need to be sectioned. (Fig.21)

Code No. Mill Workpiece Fig. 21 Date: Revised Page #
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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
4 IDENTIFYING DIMENSION SYSTEM
4.1 Size Dimensions
Emphasizes the size of an object or part
Ex. Diameters, lengths, width, height, thickness, degrees, etc. (Fig. 22)

Fig. 22
4.2 Location Dimensions

Emphasizes the relationship between two points or references.
Ex. Location of center holes.

Location of an edge from datum line. (Fig. 23)

Fig. 23

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Information Sheet 1.1.1 : Mill Workpiece ( Intermediate )
4.3 Projection lines and dimension lines
Projection lines should generate and drawn in a direction perpendicular the feature to
be dimensioned, the dimension line parallel to the straight line. Projection and projection lines
are drawn as thin continuous lines. The projection line, which shows the limits of the dimension,
must extend beyond the dimension line. The distance between the dimension lines must be
appropriate. (Fig 24 a-b)

Fig. 24a

Fig. 24b
4.4 Arrowheads

Each end of a dimension line should be carefully drawn arrowhead whose branches
should be at an angle sufficiently open to mark the extremities of the dimension line.

The size of the arrow is adjusted according to the thickness of the line. The length L of
the arrowhead is approximately 12 times the continuous thin line and shall be the same within
one drawing. (Fig. 25)

Fig. 25

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Information Sheet 4.1.1 : Milling Workpiece ( Intermediate )
Information Sheet 1.1.1: Mill Work piece ( Intermediate)

Learning Outcomes:

1 Calculate speed and feeds for milling operations

Learning Activity:

1.1 Select cutting speed and feeds for milling operations

Cutting Speed

1. As you will remember from the element
“Machining by Milling- Cutting Principles”
Cutting speed is the speed at which the
Cutting edge or tooth cuts into the workpiece.

2. Cutting speed is expressed as meters per in
(m/minute)

Code No. Date: Developed Date: Revised Page #
ALT723307
Milling Workpiece (Intermediate)

June 10,2010 1

Information Sheet 4.1.1 : Milling Workpiece ( Intermediate )

3. The cutting speed at which a milling
Operation is carried out depends on:

(i) The workpiece material:
- soft materials require a higher
Cutting speed than hard and tough
Materials.

(ii) Strength and rigidity of machine

Code No. Date: Developed Date: Revised Page #
ALT723307
Milling Workpiece (Intermediate)

June 10,2010 2

Information Sheet 4.1.1 : Milling Workpiece ( Intermediate )

4. The table below shows the Cutting speed(V) in meters per minute (m/min) for various materials, using
High Speed Steel (HSS) milling cutters of various types. They must be considered as average values
which may vary according to actual working conditions.

5. Carbide cutters are able to cut at much higher speed than HSS cutters and they are made in a variety
grades. If you are going to use a carbide cutter, ask your instructor what cutting speed you should
select, as he will have the values for the particular grade of carbide used in the cutter in your
workshop.

Code No. Date: Developed Date: Revised Page #
ALT723307
Milling Workpiece (Intermediate)

June 10,2010 3