It is a basic and simple presentation on a lathe machine.

1. Sana ullah
19-SP-00741
Comwave Islamabad

2. Outline
Lathe machine
Parts of lathe machine
Lathe machine operations
Tool Angles
References

3. Introduction
Lathe is a machine, which removes the metal from a piece of work to
the required shape and size.
• Lathe is one of the most important machine tools in the metal
working industry.
• A lathe operates on the principle of a rotating workpiece and a fixed
cutting tool.
• The cutting tool is feed into the workpiece, which rotates about its
own axis, causing the workpiece to be formed to the desired shape.
• Lathe machine is also known as “the mother/father of the entire tool
family”.

4. Construction of a Lathe

5. Parts of a Lathe Machine
The principal parts of a lathe are:-
1. Bed
2. Headstock
3. Tailstock
4. Carriage
5. Feed mechanism

6. Lathe Bed
All the parts of the lathe
such as headstock,
tailstock, carriage etc.,
are mounted on the bed.
The bed should have
sufficient weight and be of
proper material so that
the vibrations generated
during operations are
damped out.

7. Headstock
It is located at the left
hand side of the bed.
It supports the spindle
and contains a
gearbox by which the
spindle and hence the
workpiece may be
rotated at various
speeds.

8. Tailstock
It is situated at the right
hand end of the bed. It
can be moved towards
or away from the
operator.
Tailstock can be locked
in any position along the
bed of the lathe by
tightening the clamp
lever or nut.

9. Carriage
The carriage controls and supports
the cutting tool. By the help of this,
cutting tool moves away or towards
the head stock.
It has five major parts:-
a) Saddle
b) Cross slide
c) Compound slide
d) Tool post
e) Apron

10. Parts of carriage (cont.)
a) Saddle
It is an H-sapped casting mounted on the
top of the lathe so slides along the ways
between headstock and tailstock.
It carries the Cross slide and compound
slide with suitable tool post.
b) Cross slide
It is mounted on the saddle. It provides the
cross movement (towards or away from the
operator) to the cutting tool.
The cross slide can be moved by its hand wheel.

11. Parts of carriage (cont.)
c) Compound slide
It is mounted on the cross slide.
It supports the tool post.
The hand-feed is used for
taper turning operations.
d) Tool post
It is mounted above the compound slide.
It clamps the cutting tool or cutting tool
holder in a desired position.

12. Parts of carriage (cont.)
e) Apron
It is fastened to the
saddle and contains the
feeding mechanism.
 The apron hand wheel
can be turned by hand
to move the carriage
along the bed of the
lathe.

13. Lathe Machine Operations
Turning
To remove material from outside diameter of a work piece to obtain a finished
surface.

14. Lathe Machine Operations (Cont.)
Facing
To produce a flat surface at the end of the work piece.

15. Lathe Machine Operations (Cont.)
Boring
To enlarge a hole or cylindrical cavity in the job.
The hole may have been made by drilling.

16. Lathe Machine Operations (Cont.)
Drilling
To produce a hole in the work piece.
Reaming
To finishing the drilled hole.

17. Lathe Machine Operations (Cont.)
Threading
To produce external or internal threads on the
work piece.
Knurling
To produce a regularly shaped roughness on
the work piece.

18. Tool Angles
While cutting metal, the tool cuts into the workpiece, the tool angle is an
important parameter used to determine the geometry of the cutting part of the
tool.

19. Tool Angles (Cont.)
a. Rack face: The surface through which the chips on the toll flow.
b. Main flank face: The surface on the tool that opposes and interacts with the
machined surface on the workpiece.
c. Secondary flank face: The surface on the tool opposite and interacting with
the machined surface on the workpiece.
d. Main cutting edge: The intersection line between the rack face of the tool
and the main flank.
e. Secondary cutting edge: The intersection line between the rack face of the
tool and the counter flank.
f. Tool tip: The intersection of the main cutting edge and the secondary cutting
edge. The tool tip is actually a small curve or straight line, which is also called
the rounding tool tip and the chamfering tool tip.

20. References
https://www.machin
emfg.com/tool-angle-
selection-in-lathe-
cutting/
www.Slideshare.net

21. The End