Why Stainless Steel Bolts Gall

What is galling?

Galling is adhesive wear: similar metals under load can transfer material and bond at the thread contact. Stainless alloys, especially austenitic (e.g. 304, 316), are prone to it when used without lubrication or when over-torqued.

Factors that increase galling

Prevention

Use anti-seize or moly paste on threads. Avoid power-driving stainless dry at high speed. Where possible, use a different material for nut or bolt (e.g. bronze nut). Use correct torque; our Bolt Torque Calculator gives a starting point for steel—reduce slightly when using anti-seize.

FAQ

Why do stainless bolts gall?

Stainless can cold-weld when similar metals rub under load; oxide layers break and metal bonds. Galling is more likely with same alloy (e.g. 304 on 304), dry threads, and over-torque.

How do you prevent galling on stainless fasteners?

Use anti-seize or moly paste on threads, avoid over-tightening, use a different grade for nut vs bolt when possible, and ensure threads are clean and undamaged.

Can you use anti-seize with torque specs?

Lubricated threads reduce friction, so the same torque produces higher clamp load. Reduce torque by about 25% when using anti-seize, or follow manufacturer guidance.