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Cutting Speeds for High Speed Steel
(HSS) Cutting Tools
Workpiece Material Cutting Speed
(sfm)
Aluminum & alloys 300
Brass & Bronze 150
Copper 100
Cast Iron, soft 80
Cast Iron, hard 50
Mild Steel 90
Cast Steel 80
Alloy Steel, hard 40
Tool Steel 50
Stainless Steel 60
Titanium 50
Plastics 300-800
Wood 300-500
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^l`[\c`e\fecp% Refer to the MACHINERY'S
HANDBOOK for more detailed informa-
tion.
Setting RPM
To determine and set the needed cutting RPM, do
these steps:
1. Use the table in Figure 31 to determine the cutting
speed required for the workpiece material.
2. Determine the average final diameter of the
workpiece in inches, for the cut to be made.
3. Now use the following formula to determine the
closest RPM for the cutting operation:
(Cutting Speed x 4)

Diameter of Cut

4. With the calculated RPM, refer to the RPM Chart on
Page 31 and select the pulley ratio that gives you
the closest RPM to what you need.
5. DISCONNECT THE LATHE FROM POWER!
6. Release the belt tension lever (Figure 32).
7. Make sure the spindle is completely stopped
and then open the belt access door (Figure 33).
8. Move the belt to the appropriate pulley combination
that is closest to your calculated RPM. In the chart
for example, 300 RPM is needed so BC2 is selected:
9. Close the door and re-tension the belt.
=`^li\31% Cutting speed table for HSS
cutting tools.

= RPM

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Figure 33. Belt and change gear access.
Figure 32. Belt tension lever.