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Austenitic SSWrought butt-weld fittingsTG-MG-016 · Rev. 1 · October 2026

ASTM A403 WP304 — Chemical Composition & Mechanical Properties

ASTM A403 WP304 is a austenitic stainless steel grade for wrought butt-weld fittings (UNS S30400, EN / W.Nr 1.4301). This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group manufactures flanges and fittings in this grade.

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ASTM A403 WP304 at a glance

SpecificationASTM A403 WP304
Material familyAustenitic stainless steel
Product formWrought butt-weld fittings
UNS numberS30400
EN / W.Nr equivalent1.4301
Also known as304
PREN (min values)18.0
DocumentTG-MG-016 · Rev. 1 · October 2026

Typical service

General corrosion-resistant piping

Heat treatment

Solution annealed at 1040 °C min, rapid cool

Chemical composition of ASTM A403 WP304 (weight %)

C0.08 max
Mn2.00 max
P0.045 max
S0.030 max
Si1.00 max
Cr18.0–20.0
Ni8.0–11.0
Mo—

Single values are maximums unless shown as a range or “min”.

Mechanical properties

Tensile strength, min515 MPa
Yield strength, min205 MPa
Elongation, min28 %
HardnessNot specified

About austenitic stainless steel

Austenitic stainless steels are iron–chromium–nickel alloys with 16–26 % chromium and 8–22 % nickel. Nickel keeps the structure austenitic (face-centred cubic), which makes these steels non-magnetic when annealed, very tough down to cryogenic temperatures, and easy to form and weld.

Reference information compiled from the published standard for convenience. It does not replace the current edition of the governing standard, which takes precedence. Verify critical dimensions and properties before design, purchase or fabrication. Teshi Engineers & Sales Promoters (P) Ltd accepts no liability for errors or omissions.

International equivalents of ASTM A403 WP304

All equivalents
Standard systemNearest equivalent grade
USA — ASTM / ASMEASTM A403 WP304 · ASME SA-403 WP304
USA — UNSS30400
Europe — EN designationX5CrNi18-10
Europe — W.Nr1.4301
Japan — JISSUS304 / SUSF304
China — GB / NBS30408 (06Cr19Ni10)
China — old GB designation0Cr18Ni9
India — ISX04Cr19Ni9 (IS 6911)
UK — BS (withdrawn)304S31

Equivalents are the nearest commonly cited grades. Chemistry, mechanical properties and testing differ between standards — compare them before substituting one for another.

Same alloy in other product forms

Product formSpecification / grade
Forged flanges & fittingsASTM A182 F304
Seamless pipe (seamless & welded)ASTM A312 TP304
Stud bolts / boltingASTM A193 B8 Cl.1
Heavy hex nutsASTM A194 8

FAQ

ASTM A403 WP304: common questions

What is the minimum yield strength of ASTM A403 WP304?

205 MPa, with a minimum tensile strength of 515 MPa.

What is the carbon content of ASTM A403 WP304?

0.08 max %.

What is the PREN of ASTM A403 WP304?

About 18, calculated as Cr + 3.3Mo + 16N using the specification minimum values. Typical heats are a little higher.

What is the UNS number and EN equivalent of ASTM A403 WP304?

UNS S30400; the nearest European designation is W.Nr 1.4301. Equivalents are close but not identical — check the specification if substituting.

How is ASTM A403 WP304 heat treated?

Solution annealed at 1040 °C min, rapid cool.

What is the Chinese (GB) equivalent of ASTM A403 WP304?

The nearest Chinese equivalent is S30408 (06Cr19Ni10), formerly 0Cr18Ni9. Equivalents are close but not identical — compare chemistry and properties before substituting.

What is the JIS equivalent of ASTM A403 WP304?

The nearest Japanese (JIS) equivalent is SUS304 / SUSF304.

Does Teshi Group supply ASTM A403 WP304?

Teshi Group manufactures flanges and fittings in this grade. Send your size, rating and quantity to info@teshigroup.com for a quotation with EN 10204 3.1 certificates.

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