The document discusses lathe machines, which are used to shape cylindrical workpieces. It describes various lathe operations like turning, facing, drilling and threading. It explains key lathe components like the headstock, tailstock, and carriage. It also covers workholding devices, lathe types, and turning parameters that define the cutting process. Overall, the document provides an overview of lathe machines, their functions, operations and various related topics.

4. Lathe Machines
• Lathe machines or Turning machines
1. Cylindrical Surfaces
2. Flat Surfaces
Lathe is a machine, which removes the metal from a
piece of work to the required shape &size

5. Lathe Operations:
(1) Facing
(2) Turning
(3) Taper turning
(4) Chamfering
(5) Knurling
(6) Grooving or Necking
(7) Threading
(8) Parting

6. Other Operations:
Drilling
Boring
Reaming
Milling
Grinding

7. Pictorial View of Lathe

8. Pictorial View of Lathe (with various parts
marked)

9. BLOCK DIAGRAM OF LATHE
Center: A tapered metal part with a pointed end ant it supports the
work piece as it turns between the centres.

11. Parts of Lathe

12. Turning Parameters

13. Turning Parameters
3 Turning Parameters
1. Cutting Speed
2. Feed
3. Depth of Cut

14. Turning Parameters

17. Lathe Specifications

31. • Facing: To produce a flat surface at the end of
the part (i.e. at the face)

32. • Turning: To produce cylindrical or conical
surfaces

33. • Knurling: To produce cylindrical surfaces with
some surface roughness

34. Face grooving: T o cut groove on face of the job

35. Grooving or Necking: To reduce the diameter at
desired portion

36. Lathe Operations
• Turning: To produce cylindrical or conical surfaces
• Facing: To produce a flat surface at the end of the part (i.e. at the
face)
• Drilling: To produce a hole by fixing a drill bit and drill chuck
assembly in the tailstock
• Boring: To enlarge a hole made by a drilling process
• Threading: To produce external or internal threads
• Knurling: To produce cylindrical surfaces with some surface
roughness

37. Schematic Representation of
Various Lathe Operations

38. Types of Lathe

40. Simplest type of lathe : Has no gear box, lead screw
Uses: Metal spinning, Wood working like polishing

41. Most common form and automatic feed to
cutting tool
Available in large variety of sizes

42. Smaller and lighter
set on benches
Length of bed: 1.8 m and Swing 30 cm

43. More accurate with more speeds and more costly
Used for precision work : Making of small tools, dies, gauges, fixtures

44. Turret Lathe

46. Turret Lathe

48. • Manual operation is replaced by a “turret”
that holds multiple tools
– Tools are rapidly brought into action by indexing
the turret
– Tool post is replaced by multi-sided turret to
index multiple tools
– Applications: high production work that requires
a sequence of cuts on the part

49. Special Purpose Lathe
Designed for machining of special type of work pieces
Examples: Machining of locomotive wheels, fly wheels , etc.

52. Well suited for use in restricted areas
Used by Goldsmiths and Engineers for prototyping or
fabrication work
Desk top lathe
or
Table-top lathe

53. Automatic Lathe-CNC Lathe
All actions are
controlled
automatically

56. Work-Holding Devices
• Chucks
• Mandrels
• Rests
• Centres

57. Chuck: Type of clamp used to hold an object
DRILL
CHUCKS

58. Jaw
or
Dog
Chuck

59. Used for holding symmetrical work pieces
Three jaws move together

60. Used for holding Non-symmetrical and
complex work pieces

62. Six-Jaw Chuck
More jaws grip the work piece more securely

63. Independent jaw movement
Movement of all the jaws simultaneously

64. Magnetic Chuck used in Surface
Grinder
Used for holding: 1) Thin jobs
2) Ferro-magnetic work pieces

65. Collet Chuck
Used to hold small work pieces

67. Face plate: Screwed on spindle nose

68. Job
Face plate: Used for holding jobs of irregular shape
Job is fixed with bolts, nuts and straps

70. MANDRLES

71. Mandrel: Used for holding a work piece with central
hole
Examples: gear blanks, Pulleys, etc.

72. Mandrel: Solid hardened bar and usually tapered
Taper: About 0.005 mm per cm. length

77. Work piece placed on plain mandrel

80. Stepped Mandrels

82. Work piece

83. Screw Mandrels

89. RESTS
Purpose: To prevent work piece from
bending due to pressure of cut
Used when L/D > 10 or 12

91. Steady Rest

92. Work piece supported with the help of Steady rest

93. Steady Rest
Job supported with Steady rest in CNC machine

94. Follower Rest

95. Follower rest fixed to carriage

100. Refer: Production Technology by P C Sharma

103. Short external tapers with various angles of taper using
Cross Feed of Forming tool

105. Tail stock set over method or Off set method

107. Used for turning of both external and internal tapers with a
large angle of taper

121. Refer Pages : 473-478- P . C. Sharma

122. PLANING MACHINE
(PLANER)

124. PLANER

126. DRILLING MACHINE

127. Drill bit or Drill
Through holes or
blind holes can
be produced

129. Twist drills with
two cutting edges
more commonly
used
Cutting edge or
Lip

135. Lighter in weight and portable

138. Upright drilling machine

139. Features:
• Gear driven mechanism for different spindle
speeds
• Automatic or power feed device
• Can drill holes up to 75 mm in diameter and up to
350 mm deep

140. Radial Drilling Machine

142. Gang drilling machine operation with single operator

144. Features:
• Single common long table
• Very convenient because of its compactness
• Used in Mass production
• With automatic feed control, two or more
operations can be done simultaneously by one
operator

145. Adjustable Multi Spindle Drilling Machine
Drill spindles can be
adjusted and positioned at
the desired positon

146. TPLD Series Multi-Spindle CNC Plate Drilling Machine

150. Deep hole drilling machines

151. Deep hole drilling machine

160. Point angle
Lip relief or clearance angle
Helix or rake angle
Twist Drill Nomenclature

162. BROACHING

163. Broaching tool or Broach is a
multipoint cutting tool

164. Broaching Operation

165. Shapes produced by Broaching

166. Broaches are mostly made of high speed steel (HSS) and
these are expensive tools

178. Broach fixed in broach head

179. Horizontal broaching machine

189. The inserts are fastened to the right place by
mechanical means or brazed.

195. Roughing teeth remove most of the material

196. Feed is accomplished by the increased step between any two
successive teeth on the broach.

197. Rise per tooth (RPT) is also called as Step

201. THE END