what hastelloy is it there are about 11 in the index of my superalloy book?? Hastelloy is a Ni based superalloy, other alloying elements are Chrome, Moly, Cobalt followed by tungsten. these are the major hardening players. now for driling using hi quality HSS steel may be more adventagous than carbide from a shock loading standpoint. vitreous bonded AlOx wheels will do better than the resinoid bonced wheels. if you use belts they had better be SHARP, and when they dull they will only smear metal around. these alloys will chew up a AlOX vitreous wheel. Forgive me i'm reading out of Superalloys a technical guide 2nd edition Pg 193. OK stub-length screw machine drills with a accurately ground split point or rail drills are recommended fr driiling . using a dual angled lip on the drill bit will help with drilling holes accurately. T15, M33, and M36 alloy drill bits are recommended. Don't try tapping a hole in this stuff cause that hole's inner diameter is work hardened and you'll break taps off before you get a threaded hole in it. if you ream the hole tryin' to tap it is a lost cause again work hardening. Sufochlorinated cuttting fluids are recommended. be careful grinding that you don't get your edge too too hot. i realize that doesn't sound right but you can alter the micrstructure deep into this alloy in localized areas that get excessively hot. tryin' to watch my words here. any other questions cosult SUPERALLOYS A TECHNICAL GUIDE 2ND EDITION. i bought my copy when i took a class at ASM international for a reduced pirice, hope this helps out
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