Stainless steel grades chart for buyers: families and common grades

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grades · reference · buyer guide

A quick reference to the main stainless families and the grades buyers meet most often, with typical applications and caveats.

A practical map of stainless grades for buyers:

Austenitic (300 series)
• 304 / 304L — general purpose, food equipment, architecture. 304L for welded parts.
• 316 / 316L — molybdenum added; coastal, chemical, medical, food with chlorides.
• 321 / 347 — titanium/niobium stabilised for high temperature.
• 310S — high nickel/chromium for furnace and high-temperature service.

Ferritic (400 series)
• 430 — decorative, appliances, dry indoor use; magnetic, lower cost.
• 409 / 439 / 441 — automotive exhaust; 439/441 for hotter or more corrosive sections.

Martensitic
• 410 / 420 / 440C — cutlery, blades, valves, bearings; hardenable, lower corrosion resistance.

Duplex
• 2205 — high strength + chloride resistance; chemical, seawater, FGD.
• 2507 — super duplex for severe seawater and oil & gas.

Precipitation hardening
• 17-4PH (630) — high strength + moderate corrosion resistance; aerospace, medical, precision parts.

Nickel alloys / super-austenitic
• 904L, 254SMO, 6% Mo — aggressive acids and high-chloride service.

How to use the chart: identify the environment first (chlorides, temperature, acid), then the mechanical requirement (strength, hardness), then the fabrication method (welding, deep drawing). Grade selection is a trade-off between corrosion, strength, weldability and cost — not a single "best" grade.

本文由 SteelWe 编辑与行业专家整理，内容仅供行业交流参考，不构成交易或投资建议。引用请注明来源。

Stainless steel grades chart for buyers: families and common grades

A quick reference to the main stainless families and the grades buyers meet most often, with typical applications and caveats.

A practical map of stainless grades for buyers:

Austenitic (300 series)
• 304 / 304L — general purpose, food equipment, architecture. 304L for welded parts.
• 316 / 316L — molybdenum added; coastal, chemical, medical, food with chlorides.
• 321 / 347 — titanium/niobium stabilised for high temperature.
• 310S — high nickel/chromium for furnace and high-temperature service.

Ferritic (400 series)
• 430 — decorative, appliances, dry indoor use; magnetic, lower cost.
• 409 / 439 / 441 — automotive exhaust; 439/441 for hotter or more corrosive sections.

Martensitic
• 410 / 420 / 440C — cutlery, blades, valves, bearings; hardenable, lower corrosion resistance.

Duplex
• 2205 — high strength + chloride resistance; chemical, seawater, FGD.
• 2507 — super duplex for severe seawater and oil & gas.

Precipitation hardening
• 17-4PH (630) — high strength + moderate corrosion resistance; aerospace, medical, precision parts.

Nickel alloys / super-austenitic
• 904L, 254SMO, 6% Mo — aggressive acids and high-chloride service.

How to use the chart: identify the environment first (chlorides, temperature, acid), then the mechanical requirement (strength, hardness), then the fabrication method (welding, deep drawing). Grade selection is a trade-off between corrosion, strength, weldability and cost — not a single "best" grade.

本文由 SteelWe 编辑与行业专家整理，内容仅供行业交流参考，不构成交易或投资建议。引用请注明来源。