Material Machining Views: 7

Differences when machining different stainless steels and tool selection: 1) 304 (06Cr19Ni10) - the most common austenitic grade: high tack, severe work hardening, poor thermal conductivity - one of the hardest to machine. Use cobalt HSS + TiAlN or AlCrN, low speed 400-800rpm, small feed 0.05-0.1mm/rev, generous cooling. 2) 316 (06Cr17Ni12Mo2) - molybdenum-bearing, better corrosion resistance, harder than 304: tackier, more work hardening. Use cobalt HSS + AlCrN or carbide, 300-600rpm, feed 0.04-0.08mm/rev, EP cutting fluid. 3) 201 (12Cr17Mn6Ni5N) - high manganese, low nickel, cheaper, harder than 304, severe work hardening, slightly less tacky than 304. Use cobalt HSS + TiAlN, 400-800rpm, feed 0.05-0.1mm/rev. 4) 430 (10Cr17) - ferritic, nickel-free, magnetic, easier than 304: less tack, light hardening. Use cobalt HSS or standard HSS + coating, 600-1200rpm, feed 0.06-0.12mm/rev. 5) 17-4PH (05Cr17Ni4Cu4Nb) - precipitation-hardening: HRC40-50 after heat treatment, high strength, hard to machine. Annealed: cobalt HSS; hardened: carbide or CBN, 200-500rpm (hardened), small feed. Summary: austenitic (304, 316) is hardest; ferritic (430) is easier; precipitation-hardened (17-4PH) is hardest after hardening. Choose tools and parameters by exact grade - do not generalize.