Determining Correct Spindle Rpm - Grizzly G0602 Owner's Manual

Determining Correct
Spindle RPM
Failure to follow RPM and feed rate guide-
lines may threaten operator safety from
ejected parts or broken tools.
To determine the correct spindle RPM:
1. Use the table Figure 41 to determine the
cutting speed required for the material of
your workpiece.
Cutting Speeds for High Speed Steel
(HSS) Cutting Tools
Workpiece Material
Aluminum & alloys
Brass & Bronze
Copper
Cast Iron, soft
Cast Iron, hard
Mild Steel
Cast Steel
Alloy Steel, hard
Tool Steel
Stainless Steel
Titanium
Plastics
Wood
Note: For carbide cutting tools, double the
cutting speed. These values are a guide-
line only. Refer to the MACHINERY'S
HANDBOOK for more detailed informa-
tion.
Figure 41. Cutting speed table for HSS cutting
tools.
2. Measure the diameter of your workpiece in
inches and subtract the depth of the cut that
will be taken on the initial pass.
G0602 10" X 22" Benchtop Lathe
Cutting Speed
(sfm)
300
150
100
80
50
90
80
40
50
60
50
300-800
300-500
3. Use the formula in Figure 21 to determine
the needed RPM for your operation.
Note: Always round to the closest RPM
given on the spindle speed chart, and adjust
your speed as the workpiece diameter
decreases.
(SFM) x 4
1" Diameter
Figure 21. Formula to determine required
spindle speed for lathes.
Example 1
You have a piece of
stock, and you are using workpiece with a
HSS cutting tool.
Step 1:
300 (SFM from chart) x 4 = 1200
Step 2:
1200 / 0.5" (Diameter of workpiece) = 2400
RPM
Result:
The needed speed for this workpiece is
2400 RPM.
Example 2
You have a piece of 1" diameter stainless
steel stock, and you are using a workpiece
with a carbide cutting tool.
Step 1:
60 (SFM from chart) x 2 (for carbide tool) =
120
Step 2:
120 (determined SFM) x 4 = 480
Step 3:
480 / 1" (Diameter of workpiece) = 480 RPM
Result:
The needed speed for this workpiece is 480
RPM.
= RPM
⁄ " diameter aluminum
1
2
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