330 (UNS N08330, Werkstoffnummer 1.4864, DIN/EN X12NiCrSi36-16, JIS SUH330) is a high-nickel, high-chromium, silicon-bearing heat-resisting austenitic alloy, distinct from the general-purpose 300-series stainless steels in both chemistry and purpose. Where 304 or 316 use nickel mainly to stabilize austenite for corrosion resistance at room temperature, 330 pushes nickel to roughly 35-38% and adds significant silicon (around 1.0-1.75%) specifically to resist carburization, oxidation, and thermal cycling at sustained high temperatures. That combination gives 330 excellent resistance to scaling in oxidizing and carburizing atmospheres up to around 1000-1150°C (1830-2100°F), and good resistance to thermal-cycling fatigue that would crack a lower-nickel stainless.

330's typical service is furnace and heat-treating equipment: muffles, retorts, radiant tubes, furnace fixtures and baskets, and other components that see repeated heating and cooling in industrial furnace atmospheres. Some product forms in this family (often referred to as 330HC) carry a higher carbon content than the base wrought specification specifically to boost high-temperature creep and carbide-network strength in cast or heavily-loaded fixture applications — confirm the exact grade variant against mill certification if creep performance at a specific temperature is critical.

Composition reflects a high-carbon, high-Si heat-resisting 330-family variant. Standard wrought UNS N08330 typically runs Ni 34-37%, Cr 17-20%, Si 0.75-1.50%, C 0.08% max — confirm the exact grade variant against mill certification.

330 machines more like a nickel-based heat-resisting alloy than a conventional stainless, because at roughly 35-38% nickel it effectively is one. The high nickel content makes it gummy and prone to built-up edge, work hardens readily under any rubbing or dwelling at the cutting edge, and its low thermal conductivity concentrates cutting heat right at the tool tip instead of carrying it away in the chip. Silicon and any elevated carbon in the higher-carbon variants add an abrasive wear component on top of the adhesive wear typical of high-nickel alloys, so tool life is governed by both mechanisms working together.

Sharp, positive-rake carbide with a tough substrate handles 330 better than a general stainless grade — the same fundamental approach used on nickel superalloys applies here: keep the edge cutting rather than rubbing, use decisive feeds to avoid burnishing a work-hardened skin into the surface, and expect lower cutting speeds and shorter tool life than on 304 or 316. Rigid setups and generous coolant help manage both heat and built-up edge, and roughing passes should favor consistent chip load over light finishing skims that tend to harden the surface instead of removing it cleanly.

Values assume favorable cutting conditions: a well-matched insert grade, rigid tool and workpiece clamping, good-quality raw material, short tool overhang. This high-nickel alloy runs well below general 300-series stainless speeds.

Turning

Parting / Grooving

Milling