The document provides instructions for students working in a machine shop. It outlines general safety rules and procedures for operating machines like lathes. Students must wear proper protective clothing and follow instructors' directions. The guidelines specify that students can only use assigned machines and must complete jobs and paperwork on time. Proper record keeping of operations and safety are emphasized.

1. WELCOME
to
Machine Shop

2. Central Workshop
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA-8
GENERAL INSTRUCTIONS TO STUDENTS
1. Students are required to come in proper dress while attending the Workshop
sessional class. They should wear half-shirt, trouser and full shoes.
Without full shoes no one will be permitted to enter into the shop.
2. Students are required to come on time as per the timetable. They shall be marked
late if they do not turn up within five minutes of the scheduled time. Those comes
late, are to take permission from Prof. in-charge to enter into the shop.
No one will be allowed if they are late by 15 minutes in any case.
3. Students are required to follow the instructions given by the teacher concerned or
instructor strictly. They should remain present in their place of working for the
whole class unless otherwise instructed.
4. Students are required to handle only those machine allowed to them by the
instructors. Under no circumstances should any student handle machines not
assigned to him.
5. Students are required to complete the job within the time allowed to them. They
should fill in Workshop Card and hand it over to the instructor concerned each
day before entering the shop and collect it before leaving the section. Get ensured
that it is signed by the instructor and a grade is given.
One overall grade will be deducted if workshop card is lost.
6. Students are required to clean the machine and return the tools issued to them
after each day work.
7. Students are required to do the job by themselves. Instructors would only help
them in difficulty. Students should gather as much information about the machine
tools; tools, gauges, processes and other details are possible from the instructors.
8. In case of dispute, misunderstanding or difficulty, they may meet the Prof. in-
charge or Head of the Central Workshop.
9. Assessment shall be done on the basis of attendance, discipline, attitude, quality of
jobs done, report and everyday performance.
10. After each class, they are required to submit the record (like lab record) in
the subsequent class.
On completion all classes in a shop, all students are required to submit the record,
Workshop card and all jobs made by them for evaluation. Each class shop record
should consist of the following:
i. Job/ aim with figure.
ii. Raw materials required/used.
iii. Machine used & other allied machines required and its description.
iv. Description about Job holding devices used and other related holding
devises used for the concerned machine.
v. Description about the Procedure:
vi. Short description about the used and related Tools in the shop.

3. INSTRUCTION SHEET FOR MACHINE SHOP
Sub: Workshop Practice-I WS-171 0-0-3 2 credits
Workshop Practice-II WS-172 0-0-3 2 credits
JOB: Fabrication of a job involving the following operations: straight turning,
grooving, facing, taper turning and threading.
Raw materials required: Mild Steel Rod (dia. 25 mm.), of length 75 mm.
Machine tools used: Lathe Machine.
Tools required: Facing tool, Grooving tool & Threading tool.
Measuring instruments required : Steel rule, outside caliper
Procedure:
i. Get acquainted with Lathe, its operations & have a practice
ii. Mounting of the Job in a 3 Jaw chuck on Lathe
iii. Centering the job
iv. Fixing the cutting tool on tool post
v. Setting the speed belt/gear and starting of machine
vi. Facing
vii. Straight Turning (Roughing and Finishing operations)
viii. Chamfering ix) Grooving x)Taper turning
xi) Grooving xii)Threading xiii)Drilling
xiv) Boring xv) Finishing/greasing/numbering
Reference books:
i. Workshop Technology Part-1, W A J Chapman, English Language Book Society.
ii. Workshop Technology Vol-II, S.K. Hajra Choudhury, S K Bose and A.K. Hajra
Choudhury, Media Promoter & Publisher, Mumbai.
iii. Workshop Technology Vol -II, B. S. Raghuwansi , Dhanpat Rai & Co.New Delhi.
iv. Production Technology, R.K. Jain, Khanna Publisher.
2520 205 5
20φ
12φ
15φ
20φ
M12 ×1.25
‘V’ threads
18φ
10φ16φ
15

4. SAFETY FIRST

5. Safety Instructions
Before entering the workshop all are bound to adopt the safety-
precautions rules strictly to avoid any possible accidents
A. Personal safety:
i) Wear tight cloths.
ii) Wear covered footwear. Never use half shoes or
chappals.
iii) Do not run, shout and smoke inside the shop.
iv) Never place sharp materials on the shop floor.
v) Wear goggles and never wear ring or wrist watch while
working
vi) Never try to operate a machine if machine tool is not
familiar to you.
vii) Never clean the chips by bare hands.
viii) Long hair and loose clothes are dangerous for working
in running machine.
B. Machine Safety:
i) Do not start any machines before getting instruction or
permission.
ii) Never work unguarded machine.
iii) Stop immediate the machine hearing unusual sound.
iv) Never apply more load beyond the capacity of machine.
v) Never start a machine on which ‘under repair’ board is
kept.
vi) Don’t leave the machine alone while it is in automatic
mode.

6. Practice schedule and Record submission Details
WS-171 &172 L-T-P 0-0-3 2 credits 1st
and 2nd
Sem. All Branches
Subject: Workshop Practice-I and II
1. A. Practice schedule:
a. Conversant with i) different cutting tools
ii) different job holding & tool holding devices
iii) measuring instruments
iv) Different Operations, etc.
b. Conversant with starting and stopping of the machine
c. Get acquainted with terms feed, depth of cut, speed, chuck, centering, boring,
facing, grooving, rough & finish turning, taper turning, thread cutting, drilling,
chamfering, etc.
B. Record Submission:
a) Block diagram showing layout/plan view of machine shop showing different
machines present in the shop.
b) Detail drawing of machine indicating different parts
c) Drawing block diagram of different operations that will be performed.
2. A. Practice schedule:
a. Cutting of specimen
a. Mounting of job on chuck
b. Centering
c. Setting the speed belt/gear and starting of machine
d. Fixing the cutting tool on tool post
B. Record Submission:
Description about:
a. Procedure for cutting, mounting, centering speed setting, etc
b. What are the main parts of a lathe & their specific functions?
c. What is the importance of centering and how is it achieved in turning a job on a lathe?
3. A. Practice schedule:
a. Facing, Rough turning
b. Grooving
B. Record Submission:
Description about:
a. What are lathe accessories and attachments? Specify their individual functions
with sketches.
b. What is meant by cutting speed, feed and depth of cut in turning operations?
How are these cutting parameters decided?
c. How is a lathe specified?

7. 4. A. Practice schedule:
a. Finish turning, step turning
b. Drilling and boring
B. Record Submission:
Description about:
a. What cutting tools are used for the following operations:
i) Rough Turning ii) Drilling operation
iii) Chamfering operation iv) Taper turning operation
v) Boring operation vii) Thread cutting operation
b. What are the different machining operations that can be performed in a lathe?
5. A. Practice schedule:
a. Taper turning
b. Chamfering
B. Record Submission:
Description about:
a. What is the difference between straight turning & taper turning as well as rough
turning & finish turning? How are they achieved?
b. What are various taper turning methods used in practice? What is the method
adopted in your job? Describe the methods with sketches.
c. What are the differences between chamfering, facing, knurling & parting off
operations?
6. A. Practice schedule:
e. Gear setting for threading, mounting thread tool, and threading operation
d. Finishing
e. Numbering/greasing
B. Record Submission:
Description about:
a. What is the principle adopted in a lathe for thread cutting?
b. What is the specification of the thread that you have cut in your job? What was the
arrangement in the lathe for setting up for such thread cutting?
c. Give a conceptual idea with a clear diagram ‘how to protect the operator (eye,
hand and body) during cutting operation to avoid any accident.

8. Taper turning. It is an operation of producing an external conical surface on a workpiece. A small taper may be
produced with the help of a forming tool or chamfering tool; but the larger tapers are produced by swiveling the
compound rest, as shown, at the required angle or by offsetting the tail stock or by taper turning attachment.
Taper turning.
Note. If D is the larger diameter, d is the smaller diameter and L is the length of taper, as shown in Figure, then
Lathe SETTING FOR SCREW CUTTING
It has already been described earlier that it is not necessary that every lathe will be equipped with a quick-change
gearbox. Therefore, in such lathes, where such gear box is not provided, a suitable set of gears has to be found out and
mounted at the proper position for cutting threads of different pitches. Setting up of lathe For such work includes
proper holding of the job, concentric with the lathe centres, Setting of tool at proper height and mounting of the
calculated change gears at Proper locations. Figure illustrates the general set-up of the lathe for screw cutting. It is a
view from top.
General set up of lathe for screw cutting.
For cutting of threads it is necessary that for every revolution of the spindle (or work)the tool should move parallel to
the axis of the job by a distance equal to the lead of the screw to be cut. Obviously, there will be a definite ratio
between the longitudinal feed of tool and the speed of the spindle. The desired ratio is obtained with the help of the lead
screw by connecting it to the spindle through a train of gears, as shown. Now, the motion from the spindle is
transmitted to the reversing gears, then to change gears and finally to the lead screw. On engaging the split half nut the
movement of the carriage, and hence of the tool, is guided by the lead screw. This establishes a definite link between
the longitudinal tool feed and the job rotation. Normally all the lathe manufacturers provide a complete set of gears and
Through their different combinations threads of different pitches can be cut. They also usually provide a table which
serves as a guide for selecting a suitable set of change gears for cutting threads of a particular pitch without calculation.
For cutting metric threads, a special change gear bracket is to be used in place of the one used for cutting other threads.
For calculating the change gears the guiding factor, as already discussed above ,is always the establishment of a
definite ratio between spindle speed and longitudinal tool feed. In other words we can say that definite ratio is to be
Established between the speeds of spindle and the lead screw as the: latter guides the tool movement.

9. CUTTING METRIC THREADS ON ENGLISH STANDARD LEAD
SCREWS OR VICE VERSA
Many a times it may be required to cut metric threads on lathes having British Standard lead screw, i.e., the one having
its pitch in inches. In such a case, the following relation will help.
In case of a reverse requirement, i.e., when threads of British Standard pitches are to be cut on a lathe having lead
screw of metric pitch, the following relation should be used :
you know that 1 inch is equal to 25.4 mm. So, what is actually done in the above expressions (i) and (ii) is that in the
first case we have divided the ratio of the two leads by 25.4 and in the second case we have multiplied this ratio by
25.4. By doing so we have converted the unit of one lead into that of the other in order to have same units for both the
leads. Another interesting point to note is that
The reason for this is that the expression in the latter form enables us to find out the change gears very easily, because a gear of 127
teeth is always available with every lathe, whereas there will certainly create a lot of difficulty in calculating the change gears for the
reason that it is neither a whole number which can be factorized nor a gear of corresponding number of teeth is available.
Example 6.11. Calculate change gears for cutting R.B. threads of 2 mm pitch on a lathe having lead screw of 6 mm
pitch.
Like this we can have a number of solutions and every solution will give the desired result.
Example 6.12. Calculate change gears to cut L.H, threads of 1,5 mm. Pitch of the lead screw is 6 mm,

10. Detail Procedure
1. Be conversant with the machine, sequence of operations to be carried out, read the
drawings carefully, study the manuals of the machine, safety instructions, etc.
2. Issue the tool, specimen, measuring instrument, Job & tool holding devices, and safety
apparatus. Move to the machine officially allotted to you (you are responsible for this
machine; don’t allow other one to operate your machine).
3. Mount the job to the job holder (3-jaw chuck). The supplied specimen is of
approximately 80 mm. When clamping the job keep approximately 40 mm outside
from the jaw.
a. Half tight the job
b. Check the eccentricity, and confirm it looking at the end. Adjust the center by
striking it briskly by trial and error.
c. Fully tight the job.
4. Set the cutting tool.
a. Fix the cutting tool with the tool post and tighten the screws.
b. Center the cutting tool point by adjusting the height of the tool by coinciding the
cutting point of the tool with that of dead center of the tailstock.
c. Keep the tool inclined leftward for facing. The tool should perpendicular for
turning operation. In principle it should be seen that only cutting point touch the
surface of job while cutting.
d. Tighten the tool by rotating the lever.
5. Set the rpm (N, revolution per minute) of the spindle:
Cutting speed=
1000
DNπ
Where, cutting speed for mild steel is 25-30 m/min, D = diameter of job, N= rpm of
spindle to be set
Accordingly, set the two levers at A/B/C and 1/2/3 to get the desired rpm.
6. Start the machine:
Pull and give upward movement to the black colored lever switch (under the electrical
control box of carriage)
If any problem, to stop the machine, you can follow
a. Give down ward movement to the lever switch to off position (but not to the bottom
position, otherwise it will rotate in reverse direction. Middle position is the off position)
b. Push the emergency red button.
c. Press the leg brake.
7. Start working : Facing
a. Move the carriage (with tool, tool post, compound rest, cross slide) towards the job
by rotating the hand wheel of carriage anticlockwise.
b. Move the cross slide (rotating its hand wheel) to touch the cutting point at the outer
corner edge of the job.
c. Give feed to cross slide (rotate the cross slide hand wheel) till cutting tip reach the
center of the job (Simultaneously do not rotate the carriage wheel)

11. d. Take back the cutting tool outward by reversing back the cross slide hand wheel
(rotating anticlockwise)
e. Give depth of cut (for facing) by rotating the carriage hand wheel (anticlockwise).
(Remember: for turning operation depth of cut is provided by cross slide and feed by
carriage movement)
f. Give feed of cut rotating the cross slide hand wheel (clockwise) up to the center
g. Repeat the process till the face become full flat and perpendicular to the axis.
h. Stop machine.
8. Turning (to get a diameter of 20mm)
a. Set the cutting tool perpendicular to the surface of the job. (Unscrew the tool post
lever, position the tool post and tighten it properly)
b. Start the machine.
c. Just touch the cutting point on the surface of the specimen.
d. Give depth of cut (about 0.5mm) to remove the rust portion.
e. Cut up to a length of 35.00 - 40.00 mm giving feed by rotating the hand wheel of the
carriage. (Hold the hand wheel by two hand 1800
apart and rotate slowly)
f. If the rust is not properly removed, repeat the process once or more giving more depth of cut..
g. Stop the machine.
h. Measure the diameter of job accurately
i. Let the initial diameter =Di and final diameter is Df (20 mm) to be achieved.
j. Total depth to cut
2
fi DD −
=
k. Now decide in how many number of passes will be required. Accordingly give
depth of cut (by rotating the cross slide hand wheel). Adjust the depth of cut for the
last pass so as to maintain the required diameter also it should be less to get good
surface finish.
l. Stop the machine.
9. Grooving
a. Mark two lines at length 20.0 and 25.0 mm for the area to be grooved.
b. Change the tool for grooving and center it.
c. Fix the tool such that both surface of the tool will not touch the job (only point will
touch).
d. Give movement to carriage (feed) and cross slide (depth of cut) to get the groove.
10. Chamfering:
a. Inclined the tool so that the tool edge is 450
to the axis of the job. Give
approximately 1 mm depth to chamfer the sharp corner of the job to avoid injury to
the operator during holding the job.
b. Stop the machine.

12. 11. Taper turning:
a. Remove the job from the 3-jaw chuck, fix the other end so that groove portion
will just outside, center the tool as explained earlier.
b. Turn the job as explain earlier to 20 mm diameter (check: it may happen that the
created surface may not coincide with other end surface, so adjust the last depth
of cut).
c. Do the facing operation for the end as explained earlier.
d. Mark a line at 25 mm from the end where taper to be started.
e. Turn for 15.0mm diameter, the rest portion ( 25.00 mm from the end)
f. The taper will be done by Compound slide method. So, turn the base of the
compound slide as per the taper angle:
⎟
⎠
⎞
⎜
⎝
⎛ −
= −
L
dD
2
tan 1
θ , where D= larger diameter, d= smaller diameter, L = axial
length of the taper portion.
g. Set the compound rest (check the inclined angle and clamp it.
h. Give depth of cut of about 0.5 mm and give feed by compound slide hand wheel
(right to left). Do not move the carriage.
i. Repeat the process; adjust the last depth of cut to get desired taper for the length
of 25.00mm.
12. Grooving
a. Mark the lengths of 20.0mm and 25.00 mm from the end.
b. Make groove as mentioned earlier.
13. Chamfering
a. Turn the end portion (20 mm from end) to get 12.00mm diameter for thread part as
explained earlier.
b. Chamfer the end as explained earlier.
c. Stop machine.
14. Drilling and Boring
a. Fix the job in chuck and perfectly center it
b. Fix the drill beat on tailstock, position it, start the machine, advance the tailstock mandrel and
drill
c. Fix the boring bar on tool post, give required depth of cut and enlarge the drilled hole

13. 15. Threading: (Die will not be used)
a. Set the gear box as per the chart given on the machine front panel to get the desired
fine thread (M12×1.25 , ie, Outer diameter=12.00 and pitch is 1.25 mm).Remember:
If you go for course thread it will be M12×1.75, ie, outer diameter is 12.00 mm and
pitch is 1.75mm.
b. Check the rpm of the Job/spindle of machine at slow speed (about 60 rpm). Set the
lever accordingly.
c. Set the tool perpendicular to the axis of the job.
d. Start machine.
e. Just touch the tool tip to the surface of the job (to get reference line to give depth of
cut for thread height).
f. Position the tool at the end.
g. Give depth of cut about 0.2 mm (2 division).
h. Calculate the depth of thread (that is the total depth to be cut)=0.6134345×pitch.
Accordingly, decide how many numbers of passes is required, and for each pass what
is the depth of cut.
i. Remember: thread to be cut by automatic feed. So, set the lever in automatic feed
(i.e, engage the half-nut)
j. Cutting will start.
k. When the cutting will reach groove, stop machine.
l. Do not disengage the half-nut lever (otherwise thread will be destroyed)
m. Back the tool to the end by reversing the spindle rotation.
n. Give depth of cut and repeat the process till full depth of the thread is obtained.
16. Completion of the Job:
a. Finish the job by polishing it by the emery paper.
b. Grease the job to avoid rusting.
c. Number the job.
d. Clean the machine.
e. Return the tools.
f. Submit the job and Sign the job completion record
g. Submit the report within one week.