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Greenfield PM Plus™ Thread Mills
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Suggested Speeds and Feeds
| Material |
Surface
Feet Per
Minute (SFM) |
Cutter Diameter
|
| .125 |
.250 |
.375 |
.500 |
.750 |
1.000 |
| Feed
in Inches Per Tooth* |
| Aluminum |
700 plus |
0.001 |
0.002 |
0.003 |
0.004 |
0.006 |
0.008 |
| Cast
Iron |
150 |
0.0007 |
0.0015 |
0.002 |
0.003 |
0.004 |
0.006 |
| Brass
or Bronze |
400 |
0.001 |
0.002 |
0.003 |
0.004 |
0.005 |
0.006 |
| Steel
<200 Bhn |
250 |
0.0007 |
0.0015 |
0.002 |
0.003 |
0.004 |
0.005 |
| Steel
<325 Bhn |
175 |
0.0005 |
0.001 |
0.0015 |
0.002 |
0.003 |
0.004 |
| Stainless
Steel |
100 |
0.0005 |
0.0008 |
0.0015 |
0.002 |
0.003 |
0.004 |
| Tool
Steels, Soft |
125 |
0.0005 |
0.0008 |
0.0012 |
0.0015 |
0.002 |
0.003 |
* To adjust inches per minute for internal
threads:
If D1 is the major diameter of the thread
to be cut and d1 is the diameter of the cutter, then calculate the
programmed feed rate by taking ((D1-di)D1) X (calculated feed rate
(IPM) from above) Example: To cut a 5/8-18 thread with a 3/8 dia.,
4 flute cutter in Cast Iron the numbers above yield a feed rate
of 12.3 IPM. (1536 RPM x .008 ipr). The programmed feed rate would
be ((.625-.375)/.625)x12.3 = 4.9 IPM.
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