Stainless Steel · 20 thicknesses

304 Stainless Steel

304 / 304L · ASTM A240

The workhorse stainless. Excellent corrosion resistance for kitchens, medical, and architecture. Stocked in 2B, brushed #4, and hot-rolled #1 plate finishes.

Representative stainless steel parts

Thickness & specs

Pick a thickness. Every number below is for that exact gauge.
TRUMPF air bend, this gauge
Good to know
Bend deduction at standard angles inches
Values marked † are derived from our V-die geometry (die contact width) rather than measured on the brake: hole/cutout distance = the die contact region from the bend line; Z-bend spacing = minimum flange + material thickness + inside radius (45° offsets add the die lean-over). The ACB Laser minimum leg applies when optical angle measurement is required on your bend. Shorter flanges bend fine, measured with standard methods. All bend data is air-bend reference in inches. We verify on a test bend before production runs.
Design rules, this gauge
How we cut it
Corner relief is part-specific. Open Corner relief for recommendations and PDF example photos for the selected gauge. Seam gap, relief-opening size and distance from a bend line are separate dimensions; confirm the flat pattern and forming sequence.
Self-clinching hardware, this gauge
Hardware fit, this alloy & finish
Countersinking, this gauge
Tap & clearance drill chart, this gauge
Hardware hole sizes and part numbers are our own catalog figures. Hole sizes differ between PEM series, so don't cross them with another shop's chart. The mounting hole tolerance the clinch depends on is ±0.002″. Countersink fits require at least 0.010″ of material land under the cone; anything less leaves a knife edge that burrs and never seats square. Tap drills shown are the standard shop pick (75% thread inch, D−pitch metric); dial the percentage to your material on the tap & clearance drill chart.

Material properties

Reference values for the alloy family
Mechanical & physical

Reference values per the listed specification. A basis for design comparison, not guaranteed minimums for certification work. Material certs available on request.

Supported services

Feature chart

Scored 1–5 against the other alloys we stock

Material science / educational reference

Material composition

Chromium and nickel are the principal additions to the iron base. The L variant has a lower carbon limit.

Inside the material

Expand to explore

Selected wt% limits from the cited Cleveland-Cliffs 304 / 304L sheet data sheet. These producer reference values are not the complete specification for every product form.

IronBalance

The base metal. Alloying additions and processing determine the phases and structure within this iron-rich material.

Chromium18.0–20.0%

Supports the thin passive surface film responsible for stainless corrosion resistance.

Nickel8.0–12.0%

Helps stabilize the austenitic structure.

Carbon304: ≤0.08% · 304L: ≤0.03%

The lower L-grade limit reduces susceptibility to chromium-carbide-related intergranular corrosion after welding.

Only selected constituents are shown. Weight percent is mass fraction × 100. “Balance” is the remainder after all other elements; ranges and maximum limits are not amounts to add together.

Industry references & further reading

Sources explain the reference basis; they do not certify the material supplied. Reviewed September 19, 2026.

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