What are the appropriate feeds and speeds for drilling in annealed A2 tool steel? I've been drilling 17/64 holes in A2 1 1/2 deep for body clearance on 1/4 20 cap screws in a mold I've been making for epoxy granite test samples. Drill bits have been breaking or burning up left and right at 1400 RPM (figuratively, I'm not running the mill backwards).
I looked in the chart in the Morse catalog for tool steel and they say 100sfm which amounts to 1400 RPM on a 17/64 bit. The hardest tools steel they give in the chart is supposed to be 50sfm which would amount to 700 RPM.
I'm having better luck at closer to 500 RPM. I've also been using Cool Tool Cutting fluid from monroe fluid technologies.
I've noticed drilling too slow causes the material to work harden while too fast causes drills to dull or burn up. I also managed to break a 13/64 bit off in another hole so I've acquired an MA Ford Hi-Roc bit to drill out the broken drill bit and will report on how this works.