“…(2) Extensive studies continue on high speed tool steel drills , comparing LTTMT , h ITT~1T, and SlIT of steels Rl8 (0.8C-3Cr-l8W-1V or AISI Tl), RÔMS ( 0.8C-4Cr-5Mo-6W-2V), Rl2 (0.8C-3Cr-l2W-2V ) , and R6M5KS (0.8C-4Cr-5Co-SMo-6W-2V) (163) . Only a small increase in room temperature and hot hardness (1 to 2 IIRC) is observed a f t e r L1TMT , compared to IITTMT and ShIT.…”