threadmillng questions

[panaceabea]

The bulk of my work is in aluminum but Mon I have to mill 1.5 x16 tpi in 4130 anealed plate 1" thick. I am using a micro-100 carbide thread mill .
Would like advise on spindle speed and feed rate . Thanks

[Caprirs]

What is the diameter of the thread mill? That should determine a base point for speed/feed.

I just finished thread milling almost 300 holes in 304 SS, although they were a lot smaller at M8 x 1.25 x 14mm deep. I centerdrilled with a .375 spot drill to make a chamfer, then drilled, then flat bottomed the hole with an endmill. The threadmill (.235" dia) ran at 1100rpm and fed at 2ipm. Started over the center of the hole, plunged to the bottom, moved sideways to the wall, then G3 helix up two passes, back to center, retract. Thread mill looks barely used.

[panaceabea]

1/2" diam

[panaceabea]

I just found the calculator on the micro 100 site, using it I come up with spindle speed of 1910 rpm and feed of 12.73 IPM .

[Mike Stevenson]

panaceabea,

Those feeds and speeds sound okay to me.