This document discusses taper turning and facing operations on a lathe machine. It defines taper as a gradual change in diameter along the length of a workpiece. There are different methods for turning tapers, including using a form tool, tailstock set over, compound rest, or taper turning attachment. The tailstock set over method involves shifting the tailstock axis at an angle to the lathe axis. Facing involves removing metal from a workpiece face using a tool fed at a right angle to the work axis, to create a flat reference surface. Taper turning and facing are important lathe operations for creating conical shapes and flat surfaces.

1. TOPIC : LATHE -TAPER TURNING AND
FACING
NAME: SAYAN GHOSH

2. INTRODUCTION
 Lathe is a machine which removes the metal from a piece
of work to the required shape and size.
 It works on the principle of a rotating workpiece and a
fixed cutting tool.

3. Lathe parts
A lathe machine consists of various parts :-
1. Bed
2. Headstock
3. Tail stock
4. Carriage
5. Saddle
6. Cross Slide
7. Compound rest
8. Tool Post
9. Apron
10. Chuck
11. Feed rod
12. Lead Screw
13. Spindle

4. LATHE OPERATIONS
The various types of lathe operations are :-
1. Taper turning
2. Facing
3. Grooving
4. Parting
5. Threading
6. Knurling
7. Drilling
8. Reaming
9. Boring
10.Tapping

5. TAPER
Taper may be defined as the gradual increase or decrease in
diameter of a workpiece along its length.
Where,
D1 = Larger diameter of taper(mm)
D2 = Smaller diameter of taper(mm)
L = Length of taper(mm)
α= Half taper angle

6. TAPER
 Tapers are classified as inch tapers or metric tapers based on their
measuring units.
 Metric tapers are measured in millimeters per meter of length; for
example, a 1:20 taper has a 1-mm diameter change in 20mm of
length.
 Taper is necessary to
 Ensure self alignment.
 For quick fixing and releasing.
 For easy assembly and dismantle of parts.
 For transmitting drive in the assembled parts.
 Tapers are used in
 Drill shanks
 Drill sockets
 Drill sleeves
 Drill chuck
 Live centre
 Dead centre

7. TAPER TURNING OPERATIONS
 Taper turning on a lathe is the process of progressively
expanding or lowering the diameter of a cylindrical workpiece to
achieve a conical surface.
 There are five different types of taper turning methods in lathe
machines.
1. Form tool method
2. Tailstock set over method
3. Compound rest method
4. Taper turning attachment method
5. Combining feeds method

8. TAILSTOCK SET OVER METHOD
 The principle of this method is to shift the axis of rotation of the
workpiece at an angle to the lathe axis and fitting the tool parallel to
the lathe axis.
 This method is done when the body of the tailstock is made to slide on
its base towards or away from the operator by a set over screw.

9. ADVANTAGES AND DISADVANTAGES
ADVANTAGES
Power feed can be given
Good surface finish can be
obtained
Maximum length of the taper can
be produced
External threads on taper portion
can be produced
Duplicate tapers can be
produced
DISADVANTAGES
Only external taper can be turned
Accurate setting of the offset is
difficult
Taper turning is possible when work
is held between centres only
Damages to the centre drilled holes
of the work
The alignment of the lathe centres
will be disturbed
Steep tapers cannot be turned

10. FACING OPERATION
 Facing is an operation of removing metal from the work-face by feeding
the tool at right angles to the axis of the work.
 The purpose of facing is :-
 To have a reference plane to mark and measure the step lengths of
work.
 To remove the rough surface on the faces of the work and have
finished faces instead.
 To maintain the total length of the work.

11. CONCLUSION
Taper is the gradual increase or decrease in diameter
of a workpiece along its length.
Taper turning is done to provide a conical shape in the
metal.
Facing is done to provide a flat surface form which to
take accurate measurements.
Lathe is called mother of all machines as all kind of
operations can be performed here.

12. THANK YOU