Turning Workpiece (Basic)

Information Sheet 1.1.1 : Standard drawing scales, symbols and abbreviations
Learning outcomes:
1 Turn Workpiece
Learning Activity:

1. Identify standard drawing scales, symbols and abbreviations

Abbreviations and Geometrical Tolerance

Abbreviations

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Information Sheet 1.1.1 : Standard drawing scales, symbols and abbreviations
Abbreviations Used in a Blueprint

Geometrical Tolerance
Tolerance symbols are used on blueprints instead of notes
Interpreting the Tolerance Frame

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 2

Information Sheet 1.1.1 : Standard drawing scales, symbols and abbreviations
Drawing Symbols

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 3

Information Sheet 1.1.1 : Standard drawing scales, symbols and abbreviations

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 4

Worksheet 1.1.2: Abbreviations and Geometrical tolerance
Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1 Objectives

1. Identify abbreviations and geometrical tolerance used in blueprint reading.

Direction: Identify the following Symbol. Choose the letter of the correct answer.

Symbol no.1

a. Straightness
b. Flatness
c. Roundness
d. Parallelism

Symbol no.2

a. Straightness
b. Flatness
c. Roundness
d. Parallelism

Symbol no.3

a. Straightness
b. Flatness
c. Roundness
d. Parallelism

Symbol no.4

a. Parallelism
b. Concentricity
c. Symmetry
d. Squareness or Perpendicularity

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Worksheet 1.1.2: Abbreviations and Geometrical tolerance

Symbol no.5

a. Parallelism
b. Concentricity
c. Symmetry
d. Squareness or Perpendicularity

Symbol no.6

a. Parallelism
b. Concentricity
c. Symmetry
d. Squareness or Perpendicularity

Symbol no.7

a. Parallelism
b. Concentricity
c. Symmetry
d. Squareness or Perpendicularity

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 1.1.2: Abbreviations and Geometrical tolerance

Answer Key:

1. A.
2. B
3. C
4. A
5. D
6. B
7. C

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 3

Information Sheet 1.2.1 : 1st Angle Projection

Learning outcomes:
1 Turn Workpiece
Learning Activity:

1. Identify the 3 views shown by the first-angle projection
2. Describe briefly the method of projecting the 3 views
3. Interpret the blueprints reading in the first angle projection

1 . Forms of Orthographic Projections
Orthographic projection is based on two planes – one horizontal (HP)
and one vertical (VP) – intersecting each other and forming right angles
and quadrants

Only two forms of orthographic projections are use:
First-angle (‘European’) and
Third-angle (‘American’).

2. The First-Angle Projection
In first-angle projection, an object is positioned in the first-angle quadrant
between two planes.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.2.1 : 1st Angle Projection

First-angle projection ( FRONT VIEW )
First-angle projection ( PLAN VIEW )

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.2.1 : 1st Angle Projection
First-angle projection ( END VIEW ) LH

3. The First-Angle Projection Symbol

1. First-angle projection
In first-angle projection, an object is positioned in the first-angle quadrantBetween two planes.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 1.2.2: First Angle Projection
Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1 Objectives

1. Identify the 3 views shown by the first-angle projection
• Front view (Front elevation)
• Side view ( Side elevation )
• Plan

Test Your Self
1. Which is the front elevation the
drawings in Fig. 8 in the first-angle
projection?

2. Which is the correct plan for the
drawings in Fig. 6 in the first-angle
projection?

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 1.2.2: First Angle Projection

3. Which is the correct side elevation
of the drawings in Fig. 7 in the
first-angle projection?

4. The correct engineering symbol to denote the first-angle orthographic projection is

5. Choose the correct isometric view to match the orthographic drawing in first-angle
projection.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 1.2.2: First Angle Projection

6. Choose the correct drawing from A to D which represents Fig. 3 in first-angle
orthographic projection.

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Worksheet 1.2.2: First Angle Projection
Answer Key:

1. C.

2. B.
3. D.
4. B.
5. A.
6. A.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.3.1 : 3rd Angle Projection
Learning outcomes:
1 Turn Workpiece
Learning Activity:

1. Identify the 3 views shown by the 3rd-angle projection
Front view (Front elevation)
Side view ( Side elevation )
Plan

2. Describe briefly the method of projecting the 3 views
3. Interpret the blueprints reading in the third angle projection

. 1. Principal of Orthographic Projections

Orthographic projection is based on two planes – one horizontal (HP)
and one vertical (VP) – intersecting each other and forming right angles
and quadrants

Only two forms of orthographic projections are use:
First-angle(‘European’) and
Third-angle (‘American’).

Principal of orthographic projection

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Information Sheet 1.3.1 : 3rd Angle Projection

2. The Third-Angle Projection
In third-angle projection, an object is positioned in the space of the third-
angle quadrant between two principal planes.The planes are imagined to be
transparent, and the projected views of the object are viewed through the
planes.

(FRONT VIEW)

( PLAN VIEW )

Plan
Front

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.3.1 : 3rd Angle Projection
(END VIEW LH)

3. The Projection Symbol- Third-angle projection - ‘glass-box’ method

Third-angle projection

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Information Sheet 1.3.1 : 3rd Angle Projection
4. An Isometric View

5. The Third-Angle Orthographic Projection

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Worksheet 1.3.2: Third Angle Projection
Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1 Objectives

1. Identify the 3 views shown by the Third-angle projection
 Front view (Front elevation)
 Side view ( Side elevation )
 Plan

Test Your Self
1. Which is the correct side elevation
for the drawings in Fig.11 in the
3rd angle projection?

2. Which is the correct front elevation
for the drawings in Fig.10 in the 3rd angle
projection?

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Worksheet 1.3.2: Third Angle Projection

3. Which is the correct plan for
the drawings in Fig.9 in the 3rd angle
projection?

4. The symbol shown in Fig 1 is used to indicate
(A) First-angle projection
(B) Second-angle projection
(C) Third-angle projection
(D) Fourth-angle projection

5. What is the name of the view in (B) of the third angle orthographic projection drawing in
fig.4?

(A) Front view
(B) Plan view
(C) Left hand side view
(D) Right hand side view

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 2

Worksheet 1.3.2: Third Angle Projection
Answer Key:

1. A.

2. B.

3. A.

4. A. First-Angle Projection

5. C.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

Learning outcomes:
1 Turn Workpiece
Learning Activity:

1. Identify the Dimensioning, Tolerances, limits and fits

DIMENSIONING
1. Types of Dimensioning
2. Lines Used in Dimensioning
3. Dimensioning Form
4. Arrangement of Dimension

1.Types of Dimensioning
FUNCTIONAL DIMENSIONS (F)
They show the sizes that directly affect the function
of a product,eg the length of a threaded part
used in the assembly.

NON-FUNCTIONAL DIMENSIONS (NF)

They show the sizes that suit the production or
inspection work,eg a groove made on a shaft to suit
the cutting of a screw thread.

AUXILIARY DIMENSIONS (AUX)
They are included in a drawing so that the
machinist need not do any calculation and the
dimension should be enclosed in brackets,
eg the overall length of an object.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

2. Lines Used in Dimensioning
PROJECTION LINES
They are thin continuous lines.

DIMENSION LINES
They are also thin continuous lines.

ARROW HEADS
They are drawn at both ends of a dimension line.

LEADER LINES
They are used to indicate a surface or an edge.

3. Dimensioning Form

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

4. Arrangement of Dimensions

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

TOLERANCE ON DIMENSION
1. Term Used on Dimension with Tolerances
2. Types of Tolerance
3. Different Ways on Expressing Limits of Size
4. Limits Used on Angular Dimension
5. Purposes of Tolerance on a Dimension

1. Term Used on Dimension with Tolerances
BASIC SIZE - It is the size from which the limits of a size are derived

TOLERANCE - It is the difference between the high and low limits of a dimension .

Example; 25 0.05 mm 25.05 mm High Limit

- 24.05 mm Low Limit

0.10 Tolerance

2. Types of Tolerance
Unilateral Tolerance - A tolerance that is in one direction only (plus or minus)

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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits

Bilateral Tolerance - A tolerance that is in both directions (plus and minus).

Symmetrically Disposed Tolerance- A tolerance that is disposed symmetrically to the basic
size

Limits of Size in One Direction- If a dimension needs to be limited in one direction only,it
should be shown by using ‘max’ or ‘min’

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits
3. Different Ways on Expressing Limits of Size

4. Limits Used on Angular Dimension
Tolerances on linear dimensions can be used for angular dimensions

5. Purposes of Tolerance on a Dimension
• To provide the different classes of
fit in assembled parts,eg running fit

• To allow parts to be interchangeable
Spare parts such as bolts and nuts
made in different companies can be
used to replace worn-out parts in machines.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 1.1.1 : Dimensioning, Tolerances, limits and fits
• To save cost in producing part

Generally,it is impossible to produce parts to an absolute size.Therefore,it is costly and
wasteful to produce parts to a greater degree of accuracy than that specified on the blueprint.

. Turn Workpiece Date: Developed Date: Revised Page #
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Code No.
MEE722302

Worksheet 1.4.2: Dimension in Engineering Drawing

Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1 Objectives

1. Identify the various forms of dimensions in engineering drawings in accordance with the
ISO standard for Technical Drawing.

2. Identify Tolerances on Dimension

Test Your Self

1. Refer to Fig.1 below. Name the type of tolerance used?

A. Limits of size
B. Bilateral Tolerance
C. Unilateral Tolerance
D. Symmetrically Disposed Tolerance

2. Which one of the following dimensions used in engineering drawing indicates a bilateral
tolerance?
A. C.

B. D.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Worksheet 1.4.2: Dimension in Engineering Drawing
3. Which one of the following dimensions used in engineering drawing indicates a
unilateral tolerance?
A. C.

B. D.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 1.4.2: Dimension in Engineering Drawing
Answers:

1. C. Unilateral Tolerance
2. D.

3. A.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 3

Information Sheet 2.1.1: Cutting tool and Tool geometry

Learning outcomes:
1 Turn Workpiece
Learning Activity:

1. Identify cutting tool and tool geometry

Lathe CuttingTools

Introduction
It is very important to understand the metal cutting action of a lathe tool. You need to know the
different types of tool material, their shapes, and angles. If the correct tool is chosen, it will cut
well.

Parts of a High Speed Steel Lathe Tool

Figure 4.2 – Parts of a High Speed Steel Tool Bit

Right and Left Hand Cutting Tools

Lathe tools are defined as right or left hand according
to the direction in which they must travel to take a cut.
A right hand tool cuts from right to left, from the
tailstock to the headstock and the opposite for a left
hand tool. Some tools are ground so that they can cut
in either direction. The shape of the tool depends
largely on the type of operation required.

Figure 4.3 – Right Hand and Left Hand Cutting Tool

Code No. Turn workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.1.1: Cutting tool and Tool geometry

Types of Chip Formation
When cutting on the lathe, there are two forms of chips formed.

Continuous Chips

They are formed when:
 Cutting ductile work materials, such as
mild steel, copper and aluminium.
 Having a sharp cutting edge on the tool.
 Having a large rake angle on the tool.
 Using cutting fluid.
 Using fine feed (thin chip)

Figure 4.4.1 – Continuous Chip

Discontinuous Chips
They are formed when:

 Cutting brittle work materials, such as
cast iron.

 Having a small rake angle on the tool.
 Using coarse feed (Thick chip)

Figure 4.4.2 – Discontinuous Chip

Lathe Tool Angles
The shape of the tool bit is an important factor in
determining the cutting properties of a tool bit. The
tool should be sharp enough to force its way into
the work. It must also retain sufficient material
behind the cutting edge to make the tool bit strong
enough to withstand the pressure imposed on it
when cutting and the resultant heat generated.

The function the tool has to perform also

determines its shape. The following are the

common angles ground on a lathe tool bit.

Figure 4.5 – Angles Ground on a Lathe Tool Bit

Code No. Turn workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.1.1: Cutting tool and Tool geometry tool.

Top Rake Angle

The tool bits used in a lathe is designed
in such a way that the cutting point of
the tool enters the material first. The top
rake angle is ground on the face from
the nose to the back. It allows the chips
to flow away from the tool.

Figure 4.5.1 – Top Rake Angle

Side Rake Angle
The side rake angle is ground on the
face away from the side cutting edge.
It provides a sharper cutting edge and
allows the chips to flow away from the

Figure 4.5.2 – Side Rake Angle

Front Clearance Angle
The purpose of clearance angles is to allow the surface of the tool to remain clear of the work
and avoid rubbing of the tool with the work. The amount of clearance angle depends upon the
kind of cut required. The front clearance angle is ground below the front cutting edge of the
tool. It reduces the friction between the flank and the work and allows the tool to be fed into the
work.
Side Clearance Angle
The side clearance angle is ground below the side cutting edge. It reduces friction between the
flank and the work and allows the tool to cut lengthwise into the work

Figure 4.5.4 – Clearance
Angles

Code No. Turn workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.1.1: Cutting tool and Tool geometry

Approach Angle
The approach angle is the angle between the cutting edge and the cross slide axis. It can be
set by clamping the tool post in the desired position. It should be positive when used for plain
turning and negative when used for finishing square corners.

Figure 4.5.5 – Approach Angle

Nose Radius
The nose radius is ground at the tip of the tool bit to
make the tip stronger. It also improves the surface
finish of the work. In general, a 0.5mm radius
is used for roughing and a 0.1mm radius is used
for finishing. If the nose radius is too big,
it will cause chattering and if it is too small,
the tip will be weak.

Figure 4.5.6 – Nose Radius

Tool Angle Gauge
To help obtain the correct angles, a tool angle
gauge is used to measure the ground angles.

Figure 4.5.7 Tool Angle Gauge

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 4

Information Sheet 2.1.1: Cutting tool and Tool geometry

Common Lathe Tools
The following are the common tool shapes used.

Roughing Tool
The roughing tool is used to
remove material quickly. This is
used during the roughing cut where
large amounts of material are
removed.

Figure 4.6.1 – Roughing Tool

Finishing Tool
The angles of the finishing tool is similar
to the roughing tool except that is has a
bigger nose radius.

Round Nose Tool
The round nose tool is used for finishing
the wor

Figure 4.6.3 – Round Nose Tool

Parting Off Tool
The parting-off tool is used for grooving,
under-cutting and parting-off work. It
should not have any side rake angles.

Figure 4.6.4 – Parting-Off Too

Code No. Turn workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.1.1: Cutting tool and Tool geometry
Vee-Form Thread Cutting Tool
The vee-form threading tool is used for
thread cutting on the lathe. For metric
threads, the thread angle is 60 degrees.

Figure 4.6.5 – Vee-Form Thread Cutting Tool

Summary of Lathe Tool Shapes

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Information Sheet 2.1.1: Cutting tool and Tool geometry

Factors Affecting Tool Angles
The tool angles differ in the machining of different metals according to:
 The Rate of Feed - Coarse feeds for roughing require that the cutting edge be supported as

much as possible. Fine finishing feeds permit keener angles and an easier cutting action.
 The Nature of Cut - Sometimes a roughing tool has a positive side rake and a negative top

rake to ease the blow as the tool comes into contact with the work. Finishing tools required
greater top rake than side rake because the cut is more on the front than the side.
 The Nature of Metal -

Material to be Front Side Top Side Front Side
Machined Clearan Clearan Cutting Cutting
ce Rake Rake Angle Angle
Low Carbon Steel ce
Medium Carbon
Steel
High Carbon Steel
Cast Iron
Brass
Bronze
Aluminium

4.1 Lathe Tool Materials-High Speed Steel & Cemented Carbide

Not any material can be used as a lathe tool. The material chosen for must have the following
properties:

 Sufficient strength to resist the cutting forces.
 Sufficient hardness to resist wear and give an adequate life between re-grinds.
 It must retain its hardness at the high temperatures generated at the tool point when

cutting.

The two most common types of material used for making lathe tools are:

 High Speed Steel
 Cemented Carbide

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 7

Information Sheet 2.1.1: Cutting tool and Tool geometry
4.1.1 High Speed Steel ( HSS )
High Speed Steel is suitable for cutting most metals, such as mild steel, copper, bronze,
aluminium and cast iron. It is used for making lathe tools because of the following
properties:
 It is hard and tough
 It has good wear resistance
 It remains hard at high temperatures

Figure 4.8.1 – Applications of High Speed Steel
The High Speed Steel cutting tool is available in two forms.
Solid Tool
The solid tool is completely made from high speed steel and is clamped directly onto the tool
post.

Figure 4.8.1a – Solid Tool Bit

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 8

Information Sheet 2.1.1: Cutting tool and Tool geometry

Tool Bit
The tool bit is a smaller tool and is held in a tool holder which is then held in the tool post.

Figure 4.8.1b – Tool Bit Held in a Tool Holder

Cemented Carbide
Cemented Carbide tools are suitable for cutting hard and tough metals, such as stainless steel
and tool steel. It has the following properties:

 It is hard and brittle
 It has very good wear resistance
 It has better red hardness than high speed steel
 Its cutting speed can be 3 times faster than high speed steel

Figure 4.8.2 – Applications of Cemented Carbide

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 9

Information Sheet 2.1.1: Cutting tool and Tool geometry
Cemented carbide cutting tools are also available in 2 forms:

a. Tipped Tool
The tip which is made of cemented carbide is brazed onto a solid shank made of another
metal which is then held in the tool post.

Figure 4.8.2a – Tipped Tool
Throwaway Insert
The insert is held in a special tool holder which is then held in the tool post. It is indexable,
which means you can use the different corners of the insert. The insert is thrown away once all
the cutting edges are worn out.

Figure 6.6 – Throwaway Insert

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 10

Worksheet 2.1.2: Cutting tool and tool geometry

Learning outcomes:
1 Turn Workpiece
Learning Activity:

1.1 Objectives

 Identify Lathe Cutting Tools
 Identify Types of Chips Formation
 Identify Lathe Tool Angles
 Identify Common Lathe Tools
 Differentiate Lathe Tool Materials-High Speed Steel & Cemented Carbide

Test Your Self

(1.) Lathe Cutting Tools are either made of high speed steel or

A. Cemented carbide
B. Alloys
C. Granites
D. High carbon Steel

(2.) The advantage of a throw-away inserted carbide tool over a brazed-tip carbide tool is

A. It is very cheap
B. It can be thrown away when worn off
C. It can produce better surface finish
D. it does not require regrinding hence more productive

(3.) High speed steel possesses a property known as ‘red hardness’ which means they

A. can take deeper cuts
B. can produce better surface finish
C. are harder than high carbon steels
D. can retain their hardness at high temperatures

(4.) Which one of the following materials is used for making throw-away inserts?

A. Alloy steel

B. High carbon Steel

C. High speed Steel

D. Cemented carbide

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Worksheet 2.1.2: Cutting tool and tool geometry

(5) A solid tool used on the lathe is usually made of

A. tool steel
B. carbon steel
C. high speed steel
D. cemented carbide

(6.) Which condition favours the production of continuous chips?

A. Cutting tools with large rake angle
B. Cutting tools with large wedge angle
C. Cutting tools with no clearance angle
D. Cutting tools with small or negative rake angle

(7) Continuous chips are produced when

A. the tool has a small rake angle
B. cutting fluid is not used
C. cutting brittle work material
D. cutting ductile work material

(8) Cutting tool ground with too big clearance angle will

A. cause rubbing
B. weaken the tool
C. be unable to cut
D. produce rough surfaces

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 2.1.2: Cutting tool and tool geometry

Answer key:

1. A. Cemented carbide
2. D. It does not require regrinding hence more productive
3. D. Can retain their hardness at high temperatures
4. D. Cemented carbide
5. C. High speed steel
6. A. Cutting tools with large rake angle
7. D. Cutting ductile work material
8. B. Weaken the tool

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.2.1: Grinding lathe tool Figure 5.1 Bench grinder

Learning outcomes:
1 Turn workpiece
Learning Activity:

1. Identify the procedure in grinding lathe tool

Grinding High Speed Steel Lathe Tool

Bench Grinder

A Bench grinder is essentially an electric
motor with a grinding wheel mounted directly
onto the spindle. It is common to have two
grinding wheels, one on each side of the drive
motor. The two grinding wheels will have
different grinding characteristics, One will be
used for rough grinding and the other for finer
grinding.

A bench grinding machine can be mounted on
a bench. These are often called Bench
grinding machine.

Grinding Wheel
The grinding wheel is made of abrasive particles
bonded together. Most wheel used on bench
grinder aremade of silicon carbide ( Carborundum
), but aluminium oxide abrasives are sometimes
used for fine grinding.
About three-quarters of the circumference of the
grinding wheel is encased in the wheel guard. In
addition there is a screen. This adjustable and
should be used to cover as much of the exposed
part of the wheel as possible without inferring with
the grinding operation.
The tool should be adjusted so that there is just a
small gap between it and the grinding wheel. If the
gap is too large there is a danger of something (
such as your finger ! ) becoming trapped between
the tool rest and the revolving wheel.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 1

Information Sheet 2.2.1: Grinding lathe tool
Pedestal Grinder
Pedestal grinding machine sometimes have a
small tank fixed to the front of the pedestal. This
is for holding water or some other suitable
quenching fluid. Grinding generates quite a lot of
heat in the workpiece and it is necessary to cool
it from time to time. If the workpiece is not kept
sufficiently cool the temper of the metal may be
destroyed.

Features of a lathe tool.

Figure 5.3.1

Procedures for grinding HSS cutting tool
1. Grind the side cutting edge angle, while at the same time tilt the bottom of the toolbit
towards the wheel when grinding the side clearance angle.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.2.1: Grinding lathe tool

Figure 5.3.2a Side Cutting edge angle Figure 5.3.2b Side Clearance angle

2. Grind the front cutting edge to an angle slightly less than 90 and at the same time grind
the front clearance angle.

Figure 5.3.3a Front Cutting edge Figure 5.3.3b Front Clearance angle

3. Check the front clearance by placing the toolbit in the toolholder

Figure 5.3.4 Checking End Relief

4. Hold the toolbit at about 45 to the axis of the wheel and grind the side rake and back
rake angles.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 2.2.1: Grinding lathe tool
Figure 5.3.5 Back Rake angle

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MEE722302 4

Worksheet 2.2.2: Grinding tool bit
Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1 Objectives

1. Identify various features of lathe tool.

Test Your Self

A. Identify the features of lathe tool.

4

Code No. Turn workpiece Date: Developed Date: Revised Page #
MEE722302 1