CF-8M is a cast austenitic stainless steel and the casting-grade counterpart to wrought 316 — an 18-21% chromium, 9-12% nickel base with 2-3% molybdenum added for chloride pitting and crevice corrosion resistance, produced as a casting rather than rolled or forged bar. It is defined under ASTM A743/A744, carries Werkstoffnummer 1.4408, DIN/EN designation X6CrNiMo18-10, and JIS designation SCS14. As with other casting grades, silicon runs higher than the wrought equivalent to aid mold fluidity, and the as-cast microstructure is coarser and less uniform than a wrought mill product.

CF-8M is the standard casting grade wherever a 316-equivalent part needs to be cast rather than machined from bar: valve bodies, pump housings and impellers, marine and chemical processing fittings, and other pressure-containing or corrosion-service hardware exposed to chlorides or mildly aggressive chemistry. It shares 316's non-magnetic, austenitic microstructure and corrosion behavior, and cannot be strengthened by heat treatment — only cold work increases its strength.

Ranges per ASTM A743/A744. A composition table in this alloy's source content had been corrupted with data copy-pasted from an unrelated martensitic grade; it has been replaced here with verified ASTM A743 ranges.

CF-8M combines the gummy, work-hardening chip behavior of wrought 316 with the added machining wildcards of a casting: coarser and less uniform grain structure than wrought bar, possible porosity or mold-reaction inclusions near the surface, and a cast skin that is typically harder and more abrasive than the metal beneath it. The molybdenum addition that gives CF-8M its corrosion resistance also raises cutting forces and abrasive tool wear versus straight chromium-nickel CF-8, mirroring the relationship between wrought 316 and 304.

Treat the first pass into a CF-8M casting more conservatively than a repeat cut on wrought bar — the abrasive cast skin can dull an edge fast even when the underlying material machines predictably. Once through the skin, apply the same fundamentals used on wrought 316: sharp, positive-rake inserts with a stainless-specific chipbreaker, firm feeds that avoid rubbing and work hardening, and adequate coolant to offset the alloy's low thermal conductivity.

Values assume favorable conditions on sound, machined-through material. Reduce speeds for the initial skin/surface cut on castings, which is often harder and more abrasive than the core.

Turning

Parting / Grooving

Milling