- Joined
- Nov 6, 2012
- Messages
- 128
I have a Hemingway Machinists’ Hammer Kit that comes with undefined steel, bronze and aluminum, but I suspect the materials are chosen to be readily machinable. That said, the LMS calculator spits out 1910-2500 RPM (max for the 7x16 is 2500 rpm) to turn 0.5” down to 1/4” with HSS for Steel, Free Machining and 1950-2290 rpm for Steel, Low Carbon, so not much difference. But Steel, Alloy calculates to 610-1220 rpm.
I’ll use Tap Magic as cutting fluid and take shallow cuts. I’ve read that DOC should be no more than 2/3 of the cutting radius, so for a 1/32” radius that’s 0.02”. That’s about a dozen passes to turn 0.5” down to 0.25”.
What are the signs I’m cutting too slow/fast vs too deep?
BRET
I’ll use Tap Magic as cutting fluid and take shallow cuts. I’ve read that DOC should be no more than 2/3 of the cutting radius, so for a 1/32” radius that’s 0.02”. That’s about a dozen passes to turn 0.5” down to 0.25”.
What are the signs I’m cutting too slow/fast vs too deep?
BRET