Turning Workpiece (Basic)

Information Sheet 1.1.1: Other Measuring Tools
25-50mm Depth Micrometer

Interchangeable Rod

Gauge Block

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

Information Sheet 1.1.1: Other Measuring Tools
Reading of depth Micrometer

Exercise 1

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

Information Sheet 1.1.1: Other Measuring Tools
Exercise 2

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 11

Information Sheet 1.1.1: Other Measuring Tools
Telescopic Gauge

Different Sizes of Telescopic Gauge

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 12

Information Sheet 1.1.1: Other Measuring Tools
Applications of Telescopic gauge

Check the size of Telescopic Gauge

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MEE722302 13

Information Sheet 1.1.1: Other Measuring Tools
Vernier Protractor
Parts of Vernier Protractor

Applications of Vernier Protractor

Used on a surface plate

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 14

Information Sheet 1.1.1: Other Measuring Tools

Reading the Vernier Protractor

. Note the number of whole degree between
the zero on the main scale and the zero on
the vernier scale.

. Reading in the same direction, find the
line on the vernier scale that coincides
with the line on the main scale.
Multiply the number by 5 min.

Summary

1. Identify the types, parts and applications of the following measuring instrument
• Inside micrometer
• Vernier height gauge
• Depth micrometer
• Telescopic gauge
• Vernier protractor

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 15

Worksheet : 6.2.2 - Metric Outside Micrometer
Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.2 Objectives

1. Identify parts of outside micrometer
2. Describe graduations and readings of outside micrometer

Test Your Self
1.

2.

3.

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

Worksheet : 6.2.2 - Metric Outside Micrometer
4.

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

Worksheet : 6.2.2 - Metric Outside Micrometer
Answers key:

1. Reading= 3.56 mm.
2. Reading= 83.18 mm.
3. Reading=0.881 in.
4. Reading= 0.2061 in.

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

Information Sheet 7.1.1: Speed and feed in turning operation

Learning outcomes:
1 Turn workpiece
Learning Activity:
1.1 Calculate speed and feed in turning operation

A. Lathe Speed and Feed

Introduction
The selection of the proper speed and feed is the most important part of the lathe operator’s
work. It enables him to use his machine to achieve the most optimal rate possible without over
stressing the machine. Revolving the work slowly would result in the loss of valuable time while
revolving the work too fast would cause the cutting tool to break down quickly.

Use of correct speed is important to good tool life and efficient machining. Excessively high
cutting speed will cause overheating of the tool and premature cutting edge failure. Use of slow
cutting speed will reduce productivity and increase manufacturing cost.

Cutting Speed

Cutting speed is the length ( in metres ) of metal that passes the tool in one minute, measured
round the circumference of the work. For example, if a material has a cutting speed of 100
m/min, then 100 metres of the material will rotate pass the cutting tool in one minute. The
cutting speed is expressed in “metres per minute ( m / min )”.

Figure– Relationship Between Work Circumference and Cutting Speed

Factors affecting the cutting speed:

 Tool material; the harder the tool bit, the higher the cutting speed.
 Workpiece; the harder the material, the slower the speed.
 Type and shape of the cutting tool.
 Depth of cut.
 Rate of feed.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 May 31, 2010 1

Information Sheet 7.1.1: Speed and feed in turning operation

 Rigidity of work.
 The surface finish required.
 Whether cutting fluid is used.

Cutting Speed Chart for Turning

Material Being Cut Cutting Speed (m/min) Cutting Speed (m/min)
High Speed Steel Cemented Carbide
90 to 150
Mild Steel 30 to 45 80 to 120
65 to 110
Cast Iron 15 to 20 150 to 210
150 to 200
Medium Carbon Steel 30 to 35 210 - 320
150 to 200
Brass 46 to 60 45 to 60

Bronze 35 to 70

Aluminum 80 to 100

Copper 35 to 70

Alloy Steel 15 to 20

Formula for calculating Cutting Speed is;

Cutting Speed  πD x N

1000

 If the cutting speed is too high, the tool will blunt quickly and if it is too slow, more
machining time is needed.

Spindle Speed (revolution per minute) rpm

The spindle speed of a lathe is the speed at which the workpiece would be turning. Spindle
speed is normally expressed in “Revolutions per Minute (rpm)”.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 May 31, 2010 2

Information Sheet 7.1.1: Speed and feed in turning operation

Figure – Spindle Speed

Formula for calculating the Spindle Speed is;
1000 x Cutting Speed

Spindle Speed(rpm)
πxD

Nomogram
Another method of obtaining the spindle speed is by using the Nomogram. This is faster but
not as accurate. When you use the Nomogram, you need to know the following data:
 Type of cutter
 Workpiece material
 Diameter of workpiece

With the above data, you can plot the spindle speed. The next page shows you the
Nomogram.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 May 31, 2010 3

Information Sheet 7.1.1: Speed and feed in turning operation

With the Nomogram, we can find the spindle speed quickly. For example, to turn a mild steel
bar of diameter 45mm, the spindle speed would be 200rpm.

Factors affecting the Spindle Speed:

 Type, shape and condition of the cutting tool.
 Rigidity with which the cutting tool is held.
 Rigidity with which the workpiece is held.
 Depth of cut.
 Condition of the machine.
 Whether cutting fluid is used.

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MEE722302 May 31, 2010 4

Information Sheet 7.1.1: Speed and feed in turning operation

B. Feed

Feed is the distance which the tool advances along the face of the work for each revolution of
the spindle. It is expressed in millimeters per revolution (mm/rev).

Figure – Feed

Factors affecting feed:
 Work material
 Cutting tool material
 Surface finish required
 Depth of cut
 Whether cutting fluid is used

Depth of Cut

The depth of cut is the amount of in-feed moved by the cutting tool.

Figure - Depth of Cut

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MEE722302 May 31, 2010 5

Information Sheet 7.1.1: Speed and feed in turning operation

The factors that affect the selection of the depth of cut are:

 The type of material to be machined.
 The surface finish required.
 The type if cutting tool used.
 The speed and feed used.
 The size and condition of the machine.

Calculation for feed

Formula:

Feed per minute = Feed / Rev x RPM

Example: A brass Shaft of diameter 60 mm. is turned at a cutting speed of 50 mm / min.
Calculate the feed/min. of the shaft if the federate is .4 mm / rev.

Solution: Spindle speed ( rpm ) = 50 x 1000
Π x 60
= 265 rpm
= __5000___
3.1416 x 60

= _5000___
188.5

Feed per minute = Feed / rev x rpm
= .4 x 265
= 106 mm / min

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MEE722302 May 31, 2010 6

Information Sheet 7.1.1: Speed and feed in turning operation
Recommended Feed rates

Material Roughing Cut Finishing Cut
Mm / Revolution Mm / Revolution
1 Mild Steel
2 Cast Iron 0.25 – 0.50 .07 – 0.25
3 High Carbon Steel 0.4 0 – 0.65 0.13 – 0.30
4 Brass 0.25 – 0.50 0.07 – 0.25
5 Bronze 0.40 – 0.65 0.07 – 0.25
6 Aluminum 0.4 0 – 0.65 0.07 – 0.25
0.4 0 – 0.75 0.13 – 0.25

Machining Time

The machining time in turning can be calculated if the spindle speed, feed and length of cut is
known. The formula for calculating the time taken for a complete cut is:

L
Machining Time = F x N I = in minutes

Where, F= Feed of cutting tool in mm/rev
L= Length of cut in mm
N= Spindle speed in rpm

Examples;

a. Find the time required for one complete cut on a piece of work 350mm long at a spindle
speed of 300 rpm and feed rate of 0.5 mm/rev.

Time Required = 350 / (0.5 x 300)
= 2.33 min

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Information Sheet 7.1.1: Speed and feed in turning operation

b. If a shaft of 50 mm diameter is being cut at a cutting speed of 25 m/min and feed rate of 0.2
mm/rev and the length to be cut is 150 mm, find the actual time to turn the shaft.

Spindle Speed (rpm) = (1000 x Cutting Speed) /(  x Diameter of w/p)
Spindle Speed (rpm) = (1000 x 25) / (3.14 x 50)

= 159 rpm

Time Required = 150 / (0.2 x 159)
= 4.72 min.

Selection of Speed and Feed

The main influences on your selection for speed and feed:

 Material type
 Tool material type and angle
 Size and shape of workpiece
 Range of speeds
 Quantity of workpiece required
 Tool shape
 Material form (eg. Casting, bar, etc)
 Surface finish

The general guide is:

 Lower speeds for harder materials
 Lower speeds for rough cuts
 Lower speeds for long cutting edges (parting tool, form tool)
 Lower speeds for castings
 Higher speeds for harder tool materials
 Higher speeds for finishing cuts

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 May 31, 2010 8

Worksheet 7.1.2: Cutting Speed and Feed

Learning outcomes:

1 Turn Workpiece

Learning Activity:

1.1. Objectives
• Features and Uses of Common Metals
• Cutting Speed
• Recommended Cutting Speeds
• Selection of Cutting Speed
• Spindle Speed
• Relationship of RPM to Cutting Speed on Different Diameters.
• Determining Spindle Speeds from Chart (Nomogram)
• Feed
• Feeds for Various Materials
• Calculation for Feed
• Depth of Cut
• Machining Time

Test Yourself

1. The spindle speed of a machine is expressed in

(A) meters per second.
(B) meters per minute.
(C) revolutions per second.
(D) revolutions per minute.

2. Cutting speeds are expressed in

(A) meters per second.
(B) meters per minute.
(C) revolutions per second.
(D) revolutions per minute.

3. What is the spindle speed for turning a workpiece of  50 mm at a cutting speed of 30
meters per minute?

(A) 190 rpm. Turn Workpiece Date: Developed Date: Revised Page #
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Code No.
MEE722302

Worksheet 7.1.2: Cutting Speed and Feed

(B) 290 rpm.
(C) 330 rpm.
(D) 530 rpm.

4. Calculate the spindle speed for turning a shaft of  45 at a cutting speed of 30 metres
per minute.

(A) 121 rpm.
(B) 212 rpm.
(C) 424 rpm.
(D) 477 rpm.

5. Calculate the spindle speed for turning a shaft of  55 at a cutting speed of 30 meters /
min.

(A) 121 rpm.
(B) 174 rpm.
(C) 424 rpm.
(D) 477 rpm.

6. Which one of the following speeds is used for turning a 40 mm mild steel bar with a
cutting speed of 30 m/min.

(A) 200 rpm.
(B) 239 rpm.
(C) 289 rpm.
(D) 320 rpm.

7. Calculate the spindle speed for turning a 25 mm tool steel shaft at a cutting speed of
80 m/min.

(Using cemented carbide tool)

(A) 90 rpm.
(B) 100 rpm.
(C) 1000 rpm.
(D) 1018 rpm.

8. A hole diameter 15 mm is to be drilled on a workpiece of a diameter 65 mm at a cutting
speed of 22 meters per minute. Calculate the spindle speed.

(A) 73 rpm. Turn Workpiece Date: Developed Date: Revised Page #
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Code No.
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Worksheet 7.1.2: Cutting Speed and Feed

(B) 108 rpm.
(C) 217 rpm.
(D) 467 rpm.

9. Calculate the spindle speed required for drilling a 25mm hole in a 60mm workpiece.
Use the cutting speed to be 30 m/min.

(A) 150 rpm.
(B) 265 rpm.
(C) 380 rpm.
(D) 630 rpm.

10. Find the cutting speed for turning a bar 60mm at a spindle speed of 300 rpm.

(A) 57 meters/min.
(B) 60 meters/min.
(C) 69 meters/min.
(D) 80 meters/min.

11. Find the cutting speed for turning a bar of diameter 60mm at a spindle speed of 250
rpm.

(A) 47 meters/min.
(B) 60 meters/min.
(C) 69 meters/min.
(D) 80 meters/min.

12. With reference to Table , which one of the following spindle speeds is used for turning
a 40mm brass rod at 50 m/min.?

(A) 250 rpm.
(B) 320 rpm.
(C) 400 rpm.
(D) 500 rpm.

13. Calculate the feed/min of a 50mm diameter mild steel shaft if the feed is 0.25 mm/rev
and the cutting speed is 30 m/min.

(A) 12.5 mm/min.

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Worksheet 7.1.2: Cutting Speed and Feed

(B) 15.9 mm/min.
(C) 47.7 mm/min.
(D) 94.4 mm/min.

14. In turning, what is the formula used for calculating spindle speed ?

(A) Spindle Speed  1000 x Dia. Of work
(B) Spindle Speed   x cutting speed
1000 x  xDia. Of work

cutting speed

(C) Spindle Speed  1000 x Cutting speed
 x Dia of work

(D) Spindle Speed   x Dia. Of work x Cutting speed
1000

15. Calculate the machining time for a cut. The feed is 0.12 mm/rev. The spindle speed is
95 rpm. The length is 100mm

(A) 0.877 minute.
(B) 8.77 minutes.
(C) 87.7 minutes.
(D) 877 minutes.

16. The time taken to make one cut on a 180mm long workpiece at a feed of 0.25 mm/rev
and a spindle speed of 240 rpm is;

(A) 0.1875 minute.
(B) 0.75 minute.
(C) 1.3 minutes.
(D) 3.0 minutes.

17. A shaft of 45mm in diameter is turned at 25 meters/min and a feed of 0.25 mm/rev. Find
the machining time for 1 cut of 100mm long.

(A) 1.13 seconds.
(B) 2.26 seconds.
(C) 1.33 minutes.
(D) 2.26 minutes.

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Worksheet 7.1.2: Cutting Speed and Feed

18. Calculate the machining time for 1 cut of 150mm long. The spindle speed is 300 rpm
and the feed/rev of cutting tool is 0.2 mm.

(A) 1.0 minute.
(B) 2.0 minutes.
(C) 2.5 minutes.
(D) 25 minutes.

19. The cutting speed of a material to be machined is expressed in;

(A) meters per second.
(B) revolutions per minute.
(C) revolutions per second.
(D) meters per minute.

20. What is the formula used for calculating cutting speed ?

(A) Cutting Speed   x dia. of work x rpm
1000

(B) Cutting Speed   x 1000x rpm
rpm

(C) Cutting Speed   x 1000 x rpm
Dia. of work

(D) Cutting Speed   x dia. of work x rpm
1000 x 

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Worksheet 7.1.2: Cutting Speed and Feed

Answer key:

1. D. Revolution pre minute
2. B. Meters per minute
3. A. 190 rev./min.
4. B. 212 rpm.
5. B. 174 rpm.
6. B. 239 rpm.
7. D. 1018 rpm.
8. D. 467 rpm.
9. C. 380 rpm.
10. A. 57 meters/min.
11. A. 47 meters/min.
12. C. 400 rpm.
13. C . 47.7 mm/min.
14. C. Spindle Speed  1000 x Cutting speed

 x Dia of work
15. B. 8.77 minutes.
16. D. 3.0 minutes.
17. D. 2.26 minutes.
18. C. 2.5 minutes
19. D. meters per minute.
20. A .Cutting Speed   x dia. of work x rpm

1000

13. Feed/min  feed/rev x rpm
 0.25 x 1000 x cutting speed
 x dia. of work

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 6

Worksheet 7.1.2: Cutting Speed and Feed
 0.25 x 1000 x 30
 x 50
 47.7 mm/min

15. Machining Time  length to be cut
feed/rev x rpm

 100
0.12 x 95

 8.77 minutes

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

Worksheet 7.1.2: Speed and feed in turning operation
Learning outcomes:
1 Turn workpiece
Learning Activity:
1.2 Calculate speed and feed in turning operation

I. Read each problem carefully and calculate the lathe speed and feed using the following
formula

Cutting Speed  πD x N

1000

1000 x Cutting Speed
Spindle Speed(rpm)

πxD

a. What is the spindle speed suitable for turning a bar of 50mm in diameter? Take the
cutting speed as 25 metres per minute.

b. A steel shaft of 24mm diameter is turned at a cutting speed of 50 metres per minute.
Find the RPM of the shaft?

c. A piece of work of 60mm diameter is turned at 200 rpm. What is the cutting speed?

d. Calculate the spindle speed for turning a brass shaft of 35mm diameter, the cutting
speed for brass is 45 m/min.

e. What is the spindle speed suitable for turning a bar of 25mm in diameter? Take the
cutting speed as 12 metres per minute.

II. Refer to the given Nomogram. Fill up the table below of the spindle speed required given the
following data;

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302
May 31, 2010 1

Worksheet 7.1.2: Speed and feed in turning operation

Item no. Type of Cutter Material Diameter of Spindle speed
workpiece in required
Aluminum (rpm)
Brass mm.
1 High speed steel
2 High speed steel Mild Steel 90
3 Cemented carbide Mild Steel 45
4 High speed steel Cast Iron 20
5 Cemented carbide 50
10

III. Calculate the feed and machining time of the following problem:

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302
May 31, 2010 2

Worksheet 7.1.2: Speed and feed in turning operation

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302
May 31, 2010 3

Worksheet 7.1.2: Speed and feed in turning operation

Answer to worksheet:

I. Read each problem carefully and calculate the lathe speed and feed using the following
formula.

a. What is the spindle speed suitable for turning a bar of 50mm in diameter? Take the
cutting speed as 25 metres per minute.

Spindle Speed ( rpm ) = ( 1000 x Cutting Speed ) (  x Diameter of w/p )

= 159 rpm

b. A steel shaft of 24mm diameter is turned at a cutting speed of 50 metres per minute.
Find the RPM of the shaft?

Spindle Speed (rpm) = (  x Diameter of w/p )

= 663 rpm

c. A piece of work of 60mm diameter is turned at 200 rpm. What is the cutting speed?
Cutting Speed = ( 

= 38 m/min

d. Calculate the spindle speed for turning a brass shaft of 35mm diameter, the cutting
speed for brass is 45 m/min.

Spindle Speed ( rpm  x Diameter of w/p )

= 409 rpm

e. What is the spindle speed suitable for turning a bar of 25mm in diameter? Take the
cutting speed as 12 metres per minute.

Spindle Speed ( rpm ) = ( 1000 x Cutting Speed ) (  x Diameter of w/p )
Spindle Speed ( rpm ) = ( 1000 x 12 ( 3.14 x 25 )

= 153 rpm

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302
May 31, 2010 4

Worksheet 7.1.2: Speed and feed in turning operation

II. Refer to the given Nomogram. Fill up the table below of the spindle speed required given the
following data;

Item no. Type of Cutter Material Diameter of Spindle speed
workpiece in required
1 High speed steel Aluminum (rpm)
2 High speed steel Brass mm. 500
3 Cemented carbide 150
4 High speed steel Mild Steel 90 300
5 Cemented carbide Mild Steel 45 100
Cast Iron 20 300
50
10

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302
May 31, 2010 5

Information Sheet 9.1.1 : Safety on lathe

Learning outcomes:
1 Turn workpiece
Learning Activity:

1. Identify safety on lathe machine operation

Machine Shop Safety

Introduction
Machine shop safety can be divided into two broad areas of concern:
 Protection against personal injury
 Prevention of damage to tools, machines and equipment.

1. Personal Safety

Working with metals in a machine shop makes personal injury possible. Metals are hard
unyielding material. They have raggedly sharp edges. Hot, sharp metal chips produced in
cutting operations can burn and cut the operator. Rotating tools and workpieces can catch
loose clothing and hair. A careless operator can be painfully injured. Operators who think
safely and work safely can avoid these and many other hazards. They must dress properly,
follow correct work procedures and work harmoniously with fellow operators.

2. Dress Safely
 For maximum eye protection, wear clean, properly fitted; approved safety glasses with side

shields or safety goggles in the machine shop. Your eyes cannot be replaced. Protect them
at all costs.

Figure 1.3 a – Wear Eye Protection

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 9.1.1 : Safety on lathe
 Wear close fitting clothing with has short sleeves. If long sleeves are worn, they should be

rolled past the elbow.

Figure 1.3 b – Dress Properly

 Protect your feet against hot, sharp chips and sharp or falling objects. Safety boots offer the
best protection.

Figure 1.3 c – Wear Proper Footwear

 Long loose hair is dangerous around machine tools. Confine long hair under a close fitting
cap or tie it back securely.

Figure 1.3 d – Keep Hair Neat

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

Information Sheet 9.1.1 : Safety on lathe
 Rings, wrist watches, bracelets and necklaces can get caught on equipment and cause

injury. Always remove all jewellery before working with tools and equipment.
 Never wear gloves while operating machines. They are easily caught in moving parts which

can cause serious injury to the hand.
3. Safe Work Habits
 Before starting a machine, be sure that you know where the emergency stop switch is.

Figure 1.4 a – Emergency Stop Switch
location

 Make sure that all the guards are in place before you start the machine.

Figure 1.4 b – Place Safety Guards

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 9.1.1 : Safety on lathe

Keep your hands away from moving machinery and tools. Never use your hands to stop a
machine or a moving part such as the chuck. A rotating chuck is dangerous.

Figure 1.4 c – Don’t Stop Moving Parts

With your

hands

 Always make sure that the workpiece and the cutting tool is mounted securely before
starting the machine. Switch off the machine before making any adjustment on the lathe.

Figure 1.4 d – Mount Tools Securely
 Tools are sharp and dangerous. Be extra careful when using them.

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 9.1.1 : Safety on lathe
Figure 1.4 e – Safety with Tools

 It is dangerous to leave the chuck key in the chuck. Remove it immediately after use.

Figure 1.4 f – Remove Chuck Key a
after Use

 Chips are sharp and dangerous. Never remove them with your bare hands. Use a chip
rake, brush or a thin strip of wood to remove the metal chips.

Figure 1.4 g – Clear Chips with a Chip Rake

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 9.1.1 : Safety on lathe
 Always notify the training staff immediately when injured, regardless of how slight the injury

may be.

Figure 1.4 h – Report All Injuries

 Always stop machines to oil, clean, adjust or repair them. If extensive repairs are required,
disconnect the machine from its power source so that it cannot be accidentally turned on.

 Never leave a machine while it is running or in motion. Someone else may not notice that it
is still in motion and may be injured.

4. Safety Regulations

Follow these Safety Regulations when you are in a machine shop :

1. Never operate a lathe without permission.
2. Make sure that the work area is clean and free from oil or

grease. Oily floor is slippery.
3. Do not horse-play in the workshop.
4. Be alert at all times. Do not day dream.
5. Ask your training staff if you are not sure of your work.

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Information Sheet 9.1.1 : Safety on lathe
5. Care of a Lathe

Introduction

Proper maintenance, oiling and care will prolong machine life. At the end of each session, the
machine must be properly cleaned and oiled.

Figure 1.6 – Cleaning the Lathe Machine

Reasons for Oiling the Machine

Rubbing between dry surfaces causes friction and wear. Oiling creates a thin film of oil
between the moving parts of the machine. This will reduce friction, wear and also prevents
rust.

Figure 1.6.1 – Reasons for Lubricating the Lathe

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Information Sheet 9.1.1 : Safety on lathe

Common Methods of Oiling

Topping up oil level

Check the oil level before starting the lathe. The oil must be topped-up to the correct level.
Remember to use the correct type of oil. If the wrong type of oil is used, machine parts may get
damaged. Follow the instructions given in the maintenance chart.

Figure 1.6.2 – Topping-Up Oil Level

Effect of dirty oil

Always use clean oil. Dirty oil will produce more friction. Make sure the machine is free from
chips and dirt before oiling. Change the oil in the gear box as recommended by the
manufacturer.

Figure 1.6.3 – Effects of Dirty
Oil

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

Worksheet 9.1.2: Shop Safety

Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1. Objectives

1. Recognize safe and unsafe work practices in a shop
2. Identify and correct hazards in the shop area
3. Identify shop safety practices

Test Yourself

Test I. Direction. Read each item and select the best answer.

1. Identify the eye protection shown below:

(A.) Face mask
(B.) Face shields
(C.) Plain safety glasses with side shields
(D.) Plastic safety goggles

2. Identify the eye protection shown below:

(A.) Face mask
(B.) Face shields
(C.) Plain safety glasses with side shields
(D.) Plastic safety goggles

3. Identify the eye protection shown below:

(A.) Face mask
(B.) Face shields
(C.) Plain safety glasses with side shields
(D.) Plastic safety goggles

Code No. Turn Workpiece Date: Developed Date: Revised Page #
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Worksheet 9.1.2: Shop Safety

4. What are the hazards in machine shop that can cause eye injury;

(A.) Rotating/moving parts and cutters
(B.) Metal chips
(C.) Oily rags
(D.) Flammable materials

5. What safety practices that strictly prohibited in machine shop?

(A.) Wearing hairnet
(B.) Wearing goggles
(C.) Wearing jewelries
(D.) Wearing safety shoes

6. To remove chips from the work piece, you should use

(A) your fingers.
(B) a piece of rag.
(C) a chip hook.
(D) a steel rule

7. Injury to an operator working on a machine is
usually caused by

(A) using wrong cutting tool.
(B) using blunt cutting tool.
(C) operating the machine at high speed.
(D) unsafe working habits and practices.

8. You must always switch off the machine when you leave it, otherwise accident may
happen due to

(A) breakage of cutting tool.
(B) overheating of cutting tool.
(C) machine spindle speeding up.
(D) someone accidentally engaging the feed level.

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

Worksheet 9.1.2: Shop Safety

9. It is dangerous to leave the chuck key on the chuck because when the lathe is switched
on, the chuck key may

(A) damaged the bed-ways.
(B) smash the headstock.
(C) dead lock the chuck into the spindle.
(D) be thrown out and cause injuries to the operator.

10. You should not attempt to operate a lathe until you have had

(A) proper instruction.
(B) your tools checked.
(C) your machine check.
(D) a physical examination.

11. You should remove rings and wrist watches before operating a lathe because they
sometimes

(A) get lost.
(B) get damaged.
(C) damaged a piece of finished work.
(D) get caught in the moving parts of the machine

12. You should not wear loose fitting shop attire or apron because it is

(A) unsafe.
(B) unsanitary.
(C) uncomfortable.
(D) not neat in appearance.

13. You should not wear thin-soled shoes in the workshop because you may

(A) slip and fall.
(B) step on a hot chip.
(C) wear a blister on your foot.
(D) step on a piece of sharp metal.

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

Worksheet 9.1.2: Shop Safety

14. What should you do to ensure that the chuck jaws clear the lathe bed before starting
the machine?

(A) Reverse the chuck jaws.
(B) Rotate the chuck one turn manually.
(C) Try to run the machine at low speed.
(D) Remove the gap section of the gap bed.

15. To prevent the operator from touching the moving parts, machine are fitted with

(A) belts.
(B) covers.
(C) guards.
(D) lights.

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

Worksheet 9.1.2: Shop Safety

Answer Key:

1. C
2. D
3. B
4. B
5. C
6. C
7. D
8. D
9. D
10. A
11. D
12. A
13. D
14. B
15. C

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 5

Information Sheet 9.2.1: Facing, parallel, rough, finish and shoulder turning

Learning outcomes:
1 Turn workpiece
Learning Activity:

1. Explain the following lathe machine operations;
o Facing
o Parallel turning
o Rough turning
o Finish turning
o Shoulder turning
2. Explain the procedures of lathe machine operations.

Techniques in Facing, Parallel Turning, Grooving and Shoulder Turning.

Facing

Facing is done to the end of a workpiece, with the tool moving towards or away from the
operator.

Figure 7.1 - Facing

The main reasons for performing Facing are:
 To machine the end face square to the work axis.
 To make the end face flat and smooth.
 To produce the face as a datum for measurements.
 To bring the workpiece to the required length.

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

Information Sheet 9.2.1: Facing, parallel, rough, finish and shoulder turning

Figure 7.1.1 – Reason for Facing
When facing, you could cut the material from the outside to the centre or from the centre to the
outside. If the tool bit is not at the proper height, a stub will be left on the surface.
Parallel Turning
Parallel turning is done to reduce the diameter of the workpiece. This is done by feeding the
cutting tool longitudinally along the workpiece.

Figure 7.2 – Parallel Turning

To obtain the required diameter, the workpiece is turned in two stages:

Rough Turning

It is used to remove excess material quickly. Maximum amount is removed at this stage,
surface finish and accuracy is not important. (The work is turned to about 0.5 mm above the
finished size).

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

Information Sheet 9.2.1: Facing, parallel, rough, finish and shoulder turning

Figure 7.2.1 – Rough Turning

Finish Turning
This is done after rough turning, where a light cut is done. Surface finish and accuracy is of

utmost important here.

Figure 7.2.2 – Finish Turning

The purposes for performing parallel turning operations are:

 To machine the work to its required diameter.
 To produce a true cylindrical surface.

Shoulder Turning

Shoulder turning is the process of machining the surfaces between two different diameters to a
definite shape. Sometimes also called step turning, it is used to machine a step on the work.

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

Information Sheet 9.2.1: Facing, parallel, rough, finish and shoulder turning

Figure 7.3 – Shoulder Turning
Square Shoulder
It is made to allow mating parts to fit flatly onto each other.

Figure 7.3,1 – Square Shoulder
Bevelled (Angular) Shoulder
It is made to allow self-centering of mating parts.

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

Information Sheet 9.2.1: Facing, parallel, rough, finish and shoulder turning

Figure 7.3.2 – Bevelled Shoulder
Filleted Shoulder
It is made to strengthen the corner.

Figure 7.3.3 – Filleted Shoulder

Code No. Turn Workpiece Date: Developed Date: Revised Page #
MEE722302 5

Worksheet 9.2.2: Facing, Parallel turning and shoulder turning

Learning outcomes:
1 Turn Workpiece
Learning Activity:
1.1. Objectives

1. Identify the following lathe operation;
• Facing
• Parallel turning
• Shoulder turning
2. Describe the purpose and uses of the lathe operation.
3. Perform the techniques in doing the operations.

Test Yourself

Test I. Direction. Select the letter only of the correct answer.

(1) In turning, facing is carried out to

A. Machine a workpiece to the required tolerances
B. Machine a workpiece to the required diameter
C. Machine a workpiece to the required length
D. Machine a workpiece to the required radius

( 2 ) One of the purposed of parallel turning is to

A. Produce a datum edge
B. Reduce the length of the workpiece
C. Produce a true cylindrical surface
D. Machine various steps along the workpiece

( 3 ) The three common types of shoulders in turning are the square shoulder, the bevelled
shoulder and the

A. Brazed shoulder
B. Rounded Shoulder
C. Filleted Shoulder
D. Threaded shoulder

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

Worksheet 9.2.2: Facing, Parallel turning and shoulder turning

( 4 ) The purpose of a square shoulder on a workpiece is to

A. Allow a circlip to be fitted
B. Strengthen the corner
C. Allow self-centring of mating parts
D. Allow mating parts fit flatly onto each other

( 5 ) Square shoulders may be turned with a parting-off tool or a

A. Boring tool
B. Knife-edge tool
C. Roughing tool
D. Round nose tool

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