Widia GTD

Widia GTD (formerly Greenfield) PM Plus™ Thread Mills

 

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.