303 Stainless Steel Shafts

Free-machining stainless — the best balance of stainless properties and shop-floor friendliness.

At a glance

Stocked condition	Cold finished
Machinability	Good — the easiest austenitic stainless to turn
Weldability	Not recommended (sulfur)
Corrosion resistance	Good — wet and washdown duty; not for chlorides/marine
Hardening	Not heat-treatable (austenitic); work-hardens at the surface
Density (nominal)	0.290 lb/in³
Food contact	Not preferred — use 304/316 for food-contact surfaces
Magnetic	Essentially non-magnetic (slightly magnetic from cold work)

303 is 304's free-machining sibling: sulfur additions let it turn cleanly at reasonable speeds, which makes it the most economical stainless for machined shafts. For wet, washdown, and general indoor-outdoor corrosion duty, it is the default stainless pick.

The sulfur costs it a little corrosion resistance versus 304 and takes welding off the table, and like all austenitic stainless it cannot be hardened by heat treatment. When the checklist says food-contact, weldments, or marine, step to 304 or 316; otherwise 303 saves money.

Configure a 303 part →

Any geometry in the configurator — diameters, threads, keyseats, grooves, holes, tapers — can be machined in 303. Pick the material in the sidebar and the price updates live.

When to choose 303

The environment is wet or washdown and carbon steel would rust.
You want stainless at the lowest machining cost.
No welding and no food-contact requirement.

Consider instead

304 — for food-contact or welded assemblies.
316 — for chemicals, chlorides, and marine service.
416 — when you need a hardenable, magnetic stainless.

Typical applications

Washdown conveyor and roller shafts
Valve and fitting stems
Instrument and sensor shafts
Outdoor hardware pins

Frequently Asked Questions

It is not the preferred choice — its sulfur content slightly reduces corrosion resistance and it is not the standard for product-contact surfaces. Specify 304 or 316 for food, beverage, or sanitary duty.

Essentially no. Like other austenitic stainless grades it is non-magnetic, though cold-finished bar can show a faint response from work hardening.

Added sulfur breaks chips and reduces the gummy work-hardening behavior that makes 304 slow to turn. Same corrosion family, meaningfully less machine time — which shows up directly in the part price.

Stocked as 303 CF — cold finished. Material and condition are paired — each grade ships in one condition optimized for our process; see all grades on the materials page.