Grizzly G8689, Owner'S Manual

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G8689 Mini Mill (Mfg. 8/06+)
-23-
Setting RPM
It is essential to closely follow the proper cutting
speed and proper feed to reduce undue strain on
all moving parts and for operator safety.
Prior to machining, you need to determine the
RPM needed to cut your workpiece, and then set
the RPM on the machine.
To determine the needed RPM:
1. Use the table in Figure 18 to determine the
cutting speed required for the material of your
workpiece.
2. Measure the diameter of your cutting tool in
inches.
3. Use the following formula to determine the
needed RPM for your operation:
(Cutting Speed x 4) / Tool Diameter =
RPM
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
Note:
For carbide cutting tools, double the cut-
ting speed. These values are a guideline only.
Refer to the
MACHINERY'S HANDBOOK for
more detailed information.
Figure 18 .
Cutting speed table for HSS cutting
tools.
Failure to follow RPM and Feed Rate
Guidelines may threaten operator safety
from ejected parts or broken tools .
NOTICE
Failure to follow RPM and Feed Rate
Guidelines will put undue strain on mov-
ing parts, shorten tool life, and create poor
workpiece results.