304 Stainless Steel

Plain English is a quick buyer's guide. Engineer view adds the full property tables, composition and design-for-laser figures.

Overview

304 is the most widely used stainless steel — an austenitic chromium–nickel grade (around 18% chromium, 8% nickel). It offers good general corrosion resistance, excellent formability and easy welding, and is non-magnetic in the annealed state. It is the standard choice for food, catering, architectural and general indoor work. Where chlorides or marine conditions are involved, step up to 316. Where welds will not be heat-treated and corrosion matters, the low-carbon variant 304L avoids weld-zone sensitisation.

Best for

Food, catering and hygienic equipment
Architectural trim, signage and panels
Splashbacks, worktops and enclosures
Folded brackets, trays and chassis parts
Welded fabrications (indoor / general)

Less ideal for

Marine or chloride-rich environments (use 316)
Swimming-pool and coastal fittings (use 316)
High-temperature scaling service (use 309/310)
Free-machining of complex profiles (use 303)

Properties

BS EN 10088-2 · 1.4301

Physical

Density	7.93	g/cm³
Melting range	1400–1450	°C
Thermal expansion	17.3	×10⁻⁶/K
Modulus of elasticity	200	GPa
Thermal conductivity	15	W/m·K
Electrical resistivity	0.73	µΩ·m

Mechanical

Tensile strength	520–720	MPa
Proof stress (0.2%)	210 min	MPa
Hardness	≤215	HB
Elongation A50	45 min	%

Cold-rolled sheet, annealed (typical; figures vary with thickness)

Chemical Composition

BS EN 10088-2 · 1.4301 (X5CrNi18-10)

Fe Cr Ni Mn Si N C P S

Element		% present
Iron	Fe	Balance
Chromium	Cr	17.5 – 19.5
Nickel	Ni	8.0 – 10.5
Manganese	Mn	0.0 – 2.0
Silicon	Si	0.0 – 1.0
Nitrogen	N	0.0 – 0.11
Carbon	C	0.0 – 0.07
Phosphorus	P	0.0 – 0.045
Sulphur	S	0.0 – 0.015

Formability & Fabrication

304 forms exceptionally well cold — it bends, folds and deep-draws cleanly, though it work-hardens fast, so tight bends need more force than mild steel and may need annealing between heavy operations. It welds readily by TIG and MIG with no pre-heat. On thicker sections that will not be solution-annealed after welding, prefer 304L (or a stabilised grade) to avoid weld-zone sensitisation and the risk of intergranular corrosion.

Cold working

Excellent

Bending

Excellent

Deep drawing

Excellent

Arc / TIG / MIG

Excellent

Resistance weld

Good

Brazing

Good

Soldering

Fair

Machinability

Fair

Recommended filler: 308L (ER308L) for most 304 and 304L welds; 309L when joining 304 to mild or carbon steel. Match low-carbon fillers to low-carbon parents to keep corrosion resistance through the weld.

Corrosion Resistance

304 carries a self-healing chromium-oxide film that gives good resistance to food, fresh water, most foods and indoor atmospheres — the reason it dominates catering and architectural work. Its weakness is chlorides: salt, marine air and pool chemicals can pit and crack it, so coastal or marine parts should use 316. Avoid prolonged contact with chloride-bearing cleaners and keep the surface passive and clean.

Environment	Suitability
Indoor / dry atmospheric	Excellent
Food & beverage contact	Excellent
Fresh water	Excellent
Outdoor / rural atmospheric	Good
Industrial / chemical	Fair
Marine / chloride / salt	Poor

Typical Applications

Catering & food equipment Splashbacks & worktops Architectural trim & signage Sinks, tanks & vessels Enclosures & control panels Folded brackets & trays Handrails & balustrades Decorative & display parts

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Laser Cutting & Ordering

at Metal Parts Direct

Thicknesses we cut

0.9 mm1.2 mm1.5 mm2 mm2.5 mm3 mm4 mm5 mm6 mm8 mm10 mm12 mm15 mm20 mm

Cut tolerance

±0.25 mm up to 20 mm, ±0.5 mm above

Max part size

1000 × 1000 mm

Max part weight

No maximum

Estimated delivery if ordered today

Friday 28th August 2026 – Monday 31st August 2026

UK-made Laser cut to your spec No minimum order Material certs on request

Design-for-laser quick reference

These are the exact minimums the Part Builder enforces as you design, relative to sheet thickness — so your part and your quote never disagree.

Feature	Minimum
Min hole / bore Ø	0.7 × thickness (min 1 mm)
Min slot / opening width	0.7 × thickness (min 1 mm)
Min web / wall between cuts	0.7 × thickness (min 1 mm)
Min cut-to-edge distance	0.7 × thickness (min 1 mm)

Frequently Asked Questions

What is the difference between 304 and 316?

Both are austenitic stainless steels, but 316 adds around 2% molybdenum, which gives much better resistance to chlorides — salt, marine air and pool chemicals. Choose 304 for food, indoor and general work; choose 316 for coastal, marine or chloride-rich conditions.

Is 304 stainless steel magnetic?

In the annealed state it is essentially non-magnetic. Cold work — such as heavy bending, folding or deep drawing — can make it slightly magnetic at the worked areas, which is normal and does not affect corrosion resistance.

What is the difference between 304 and 304L?

304L is the low-carbon version (carbon held to about 0.03% rather than 0.07%). The lower carbon reduces the risk of weld-zone sensitisation, so 304L is preferred for thicker welded parts that will not be solution-annealed afterwards. Properties are otherwise very similar.

Is 304 suitable for outdoor or marine use?

It is fine for most rural and inland outdoor work, but it is not a marine grade. Salt and chlorides can cause pitting and staining, so for coastal, marine or swimming-pool fittings use 316 instead.

What do the 2B, DP1 and hot-rolled finishes mean?

2B is the standard cold-rolled mill finish — smooth, mildly reflective and ready to use. DP1 is the same sheet supplied with a protective laser film that stays on during cutting and handling to guard the surface, then peels away to leave a clean, mark-free face. Hot-rolled (1D/plate) is the thicker-gauge form, with a duller descaled surface, chosen where section thickness matters more than appearance.

Equivalents

Also designated

1.4301 AISI 304 S30400 UNS S30400 X5CrNi18-10

Cross-references are indicative and may not be exact equivalents — confirm against the certificate for critical work.

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This data is indicative and provided in good faith from recognised EN standards and industry references. It is not a substitute for the full specification or material certificate; mechanical properties in particular vary with temper, form and dimension. Material supplied will conform to the relevant applicable standards but may differ from these figures. No liability is accepted for actions taken in reliance on this guide. Confirm critical values against the certificate for your delivery.