This document describes the turning process used in lathes. Turning involves using a single-point cutting tool to remove material from a rotating workpiece to create a rotationally symmetric shape. The main types of cuts described are facing, contour turning, chamfering, parting/grooving, and threading. Additional details provided include descriptions of right and left hand tools, the components of an engine lathe including the chuck, and an overview of a turret lathe which holds multiple tools to rapidly perform a sequence of cuts.

1. TURNING
 A single point cutting tool removes material from a
rotating workpiece to generate a rotationally
symmetric shape
 Machine tool is called a lathe
 Types of cuts:
 Facing
 Contour turning
 Chamfering
 Parting (Cut-off) / Grooving
 Threading
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2. TURNING PARAMETERS ILLUSTRATED
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Figure 22.5 - Turning operation [Groover (2004), p.503]

3. FACING
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Figure 22.6 (a) facing
Tool is fed
radially inward

4. CONTOUR TURNING
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Instead of feeding the
tool parallel to the axis
of rotation, tool follows a
contour that is not
necessarily straight
(thus creating a
contoured form).
Figure 22.6 (c) contour turning

5. RIGHT & LEFT HAND TOOLS
 Right Hand Tool:
 Cuts from right to left
 Left Hand Tool:
 Cuts from left to right
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6. CHAMFERING
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Cutting edge
cuts an angle on
the corner of the
cylinder, forming
a "chamfer"
Figure 22.6 (e) chamfering

7. PARTING (CUTOFF) / GROOVING
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Tool is fed
radially into
rotating work at
some location to
cut off end of
part, or provide a
groove
Figure 22.6 (f) cutoff

8. THREADING
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Pointed form tool
is fed linearly
across surface of
rotating workpart
parallel to axis of
rotation at a large
feed rate, thus
creating threads
Figure 22.6 (g) threading

9. ENGINE LATHE
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Figure 22.7
Diagram of
an engine
lathe,
showing its
principal
components

10. CHUCK
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Manufacturing Systems
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Figure 22.8 (b) three-jaw chuck

11. TURRET LATHE
 Tailstock replaced by “turret” that
holds multiple tools
 Tools rapidly brought into action by
indexing the turret
 Tool post replaced by four-sided turret
to index four tools
 Applications: high production work that
requires a sequence of cuts on the part
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