strange happenings when cutting a thread on 416 barrel steel.
shown is a 10x magnification of a 1/2-28 thread.
Any thoughts why the right side looks like a 45 degree angle while the left is a nice 30 degree cut?
Anyone ever experience this.
1. Compound set at 29.5
2. .005" per pass / .002" for final pass
3. Cutting oil was used / (brushed on)
4. AR Warner T-15 insert used with 10 rake on top.
Looks like deflection except the load theoretically:
Toolbit moving to the left, pushing into the left side should prevent any right side deflection.
Correct?
Any thoughts or tips would be appreciated.
IE: Should I set the compound to 20 degrees?
Used carbide instead?
Use flat top insert with no backrake?
FYI I cut and threaded a piece of aluminum to double check my setup and it cuts proper and the thread looks great with a 30 degree angle on both sides.