Nitronic 60 (UNS S21800): Galling-Resistant Stainless Steel for Fasteners

ASTM A276 / AMS 5848 · Published: 2026-06-01 · Updated: 2026-06-02

Nitronic 60 (UNS S21800) is a high-manganese austenitic stainless steel engineered specifically for anti-galling and anti-seizing properties in sliding contact with itself or other stainless steels. Its galling resistance is qualitatively superior to all standard austenitic (304, 316) and martensitic (410, 420) grades — critical for threaded fasteners, valve stems, and pump shafts where stainless-on-stainless contact routinely galls and seizes. The alloy achieves its galling resistance through a combination of high work-hardening rate, low stacking fault energy (promoting planar slip rather than cross-slip), and a self-replenishing oxide film rich in silicon and manganese.

Compared to Type 304: Nitronic 60 has approximately 2× the yield strength at room temperature (380 MPa vs 205 MPa annealed) and superior wear resistance. Its corrosion resistance in chloride environments falls between 304 and 316 — the high manganese content does not degrade pitting resistance as much as its lower chromium (16-18% vs 18-20% for 304) would suggest. Primary applications: threaded fasteners and bolting, valve stems and seats, pump shafts, wear rings, and chain links where stainless steel components must slide against stainless steel counterfaces without galling.

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