LATHE ACCESSORIES PPT BY POLAYYA CHINTADA

1. LENDI INSTITUTE OF ENGINEERING
AND TECHNOLOGY
METAL CUTTING AND MACHINE TOOLS
COURSE CODE: C302
REGULATION: R16
3rd BTECH 1st SEM
PREPARED BY :
POLAYYA CHINTADA M.TECH,M.B.A,(PhD)
ASSISTANT PROFESSOR
TOPIC:
LATHE ACCESSORIES

2. METAL CUTTING AND MACHINE
TOOLS SYLLABUSUNIT 2:
Engine lathe – principle of working, specification of lathe – types of lathe – work holders tool holders – box
tools taper turning, thread turning – for lathes and attachments, constructional features of speed gear box and
feed gear box.
Turret and capstan lathes – collet chucks – other work holders – tool holding devices – box and tool layout.
Principal features of automatic lathes – classification – single spindle and multi-spindle automatic lathe – tool
layout and cam design for automats. s
make the students understand
Types of lathes, Lathe operations,
Work holders, Tool holders, Lathe
attachments& Automatic Lathes
COURSE OBJECTIVE: COURSE OUTCOME:
Understand the Lathe
operations Using
Lathe Machine,
APPLICATIONS:
Learned how to Use
Lathe Tools and
Importance of Lathe
Machines.

3. LATHE ACCESSORIES:
Additional devices essentially required for that machine’s general
functioning, mainly for properly holding and supporting the
workpiece and the cutting tool. Are as follows..
• Chucks
• Face plate
• Lathe dogs
• Drive plates
• Centers
• Mandrels
• Steady and follower rests

4. LATHE ACCESSORIES:
Chucks:• It is an important device used for holding work piece in lathes.
• The work pieces which are too short to be held between centres are clamped in a chuck.
• The internal threads in the chuck fit on to the external
threads on the spindle nose.
• It is attached to the lathe spindle by means of two bolts with the back plate screwed on to the
spindle nose.
• Chucks can be power or manually actuated with a chuck wrench.
• There are different chucks are there like
• 3-jaw chuck
• 4-chuck
• Combination chuck
• Collet chuck
• Magnetic chuck
• Hydraullic chuck

5. LATHE ACCESSORIES:
THREEJAWCHUCK
•The three jaw chuck as shown in Fig. is also called self-
centering chuck or scroll chuck.
•Thus chuck is used for holding round and hexagonal work.
•the three jaws move simultaneously when adjusted BY THE
CHUCK WRENCH
•They are usually provided with two sets of jaws, one for
outside chucking and the other for inside chucking

6. LATHE ACCESSORIES:
fourJAWCHUCK
•four- jaw independent chuck has four jaws; each of which
can be adjusted independently by a chance wrench
•This type of chuck can hold square, round and irregular
shape of work in either a concentric or eccentric position
•The jaws can be reversed to hold work by the inside
diameter.

7. •LATHE ACCESSORIES:
 it has a cylindrical bushing known as collet.
 It is made of spring steel and has slots cut
lengthwise on its circumference. So, it holds the
work with more grip.
Collet chucks are used in capstan lathes and
automatic lathes for holding bar stock in
production work.
 Used to hold small work pieces
 types: A collet draw-in collet & push out
collet
Collet chuck

8. LATHE ACCESSORIES:
magneticCHUCK
•magnetic chuck is Used to hold thin jobs by
magnetic forces
•Magnets are adjusted inside the chuck to hold or
release the work
•In the ON position, the flux passes through the work
piece and grips it. In OFF position the magnets are set
aside bringing them in contact with high permeable ”
keepers” which short-circuit the flux and prevent them
from passing through the work piece.

9. LATHE ACCESSORIES:
Air or Hydraulic Operated Chucks
This type of chuck shown in the figure. It is used in mass production
work for its fast and effective gripping capacity.
The mechanism incorporates a hydraulic or air cylinder mounted at the
back end of the headstock spindle and rotates with it.
Fluid pressure is delivered to the cylinder by operating a valve with a
lever and the piston will slide within the cylinder.
The movement of the piston is transmitted to the jaws by a connecting
rod and links and the jaws grip the workpiece securely.

10. LATHE ACCESSORIES:
Drill Chuck
A drill chuck is sometimes used in a lathe
for holding straight shank drill, reamer, or
tap for drilling, reaming, or tapping
operation.
The chuck is held either in headstock or
tailstock spindle. It has centering jaws
which have operated by rotating a key.

11. LATHE ACCESSORIES:
Combination Chucks :
Combination Chucks These chucks have the features of the self
centering type, as well as independent type.
This enables the jaws to achieve a self centering clamping and, be
adjusted separately. This can be helpful in mass production of
difficult shaped work piece.
The jaws are operated individually by separate screws or
simultaneously by the scroll disc.
The frame has teeth cut on its underside which meshes with the
scroll and all the jaws together with the screws move radially when
the scroll is made to rotate by a pinion.

12. LATHE ACCESSORIES:
Face plate
• Faceplate is used to hold large, heavy
and irregular shaped workpieces which
can not be conveniently held between
centres.
• It is a circular disc bored out and
threaded to fit to the nose of the lathe
spindle.
• It is provided with radial plain and ‘T’ –
slots for holding the work by bolts and
clamps.

13. LATHE ACCESSORIES:
Angle Plate
• An angle plate is simply a cast iron plate with to faces planed at right angles
to each other and having slots in various positions for the clamping bolts.
• It is always used with the face plate for holding such parts which cannot be
clamped against the vertical surface of the face plate.

14. LATHE ACCESSORIES:
a) The drive plate, as shown in Fig. is a circular plate
which is bored out and threaded so that it can be
attached to the spindle nose.
b) It also carries a hole for the pin which is used only
when the work is held in a lathe dog having straight
tail. When bent-tail dog is used, this pin is taken
out and the bent portion of the tail is inserted into
the hole
Driving plate

15. LATHE ACCESSORIES:
Lathe dog or carrier
a) The work placed on a mandrel or held between centres is
rotated positively by clamping the dog or carrier to the end of
the work.
b) This is engaged with a pin attached to the drive plate or
face plate.
c) The lathe dog or carrier may be of straight type or bent
type as shown in Fig.

16. LATHE ACCESSORIES:
Follower rest
It is “c” type in shape.
Two adjustment jaws to support the workpiece.
It is fitted on the rear portion of the carriage by bolt,
hence it moves along with the carriage.
 Used during the finishing operations or for carrying out
turning along the entire length of the jaw.

17. LATHE ACCESSORIES:
 The base is made up of cast iron.
 It is clamp on the lathe bed where the work
piece is to be supported.
 Three jaws are provided.
All jaws can be radially moved with
independent screw.
It stands stationary from a rigid
mounting on the bed, and it supports the
workpiece at the rest’s center, typically
with three contact points 120° apart.
Steady rest

18. LATHE ACCESSORIES:
mandrels
mandrel is used to hold and rotates hollow jobs
The lathe mandrel is a cylindrical bar with centre hole at each end
The work revolves with the mandrel
Types of Mandrels:
•Plain Mandrel
•Step Mandrel
•Collar Mandrel
•Screwed Mandrel
•Cone Mandrel
•Expansion Mandrel
18

19. LATHE ACCESSORIES:
mandrels
19

20. LATHE ACCESSORIES:
centers

21. Yours:
POLAYYA CHINTADA M.TECH,M.B.A,(PhD)
ASSISTANT PROFESSOR