ISO 9001:2015IBR ApprovedEstablished 1971Full Material Traceability
GroupRequest a quote
Austenitic SSWrought butt-weld fittingsTG-MG-063 · Rev. 1 · October 2026

ASTM A403 WP310S — Chemical Composition & Mechanical Properties

ASTM A403 WP310S is a austenitic stainless steel grade for wrought butt-weld fittings (UNS S31008, EN / W.Nr 1.4845). This sheet summarises its chemical composition limits, minimum mechanical properties, heat treatment and typical service. Teshi Group manufactures flanges and fittings in this grade.

Download PDF Request a quoteA4 · Teshi Group document TG-MG-063 · © Teshi Group · controlled document

ASTM A403 WP310S at a glance

SpecificationASTM A403 WP310S
Material familyAustenitic stainless steel
Product formWrought butt-weld fittings
UNS numberS31008
EN / W.Nr equivalent1.4845
Also known as310S
PREN (min values)24.0
DocumentTG-MG-063 · Rev. 1 · October 2026

Typical service

High-temperature stainless butt-weld fittings

Heat treatment

Solution annealed 1040 °C min, rapid cool

Chemical composition of ASTM A403 WP310S (weight %)

C0.08 max
Mn2.00 max
P0.045 max
S0.030 max
Si1.00 max
Cr24.0–26.0
Ni19.0–22.0
Mo0.75 max

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

Mechanical properties

Tensile strength, min515 MPa
Yield strength (0.2 % offset), 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 WP310S

All equivalents
Standard systemNearest equivalent grade
USA — ASTM / ASMEASTM A403 WP310S · ASME SA-403 WP310S
USA — UNSS31008
Europe — EN designationX8CrNi25-21
Europe — W.Nr1.4845
Japan — JISSUS310S
China — GB / NBS31008 (06Cr25Ni20)
China — old GB designation0Cr25Ni20
India — ISX04Cr25Ni20 (IS 6911)
UK — BS (withdrawn)310S16

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
Seamless & welded pipeASTM A312 TP310S

FAQ

ASTM A403 WP310S: common questions

What is the minimum yield strength of ASTM A403 WP310S?

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

What is the carbon content of ASTM A403 WP310S?

0.08 max %.

What is the PREN of ASTM A403 WP310S?

About 24, 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 WP310S?

UNS S31008; the nearest European designation is W.Nr 1.4845. Equivalents are close but not identical — check the specification if substituting.

How is ASTM A403 WP310S heat treated?

Solution annealed 1040 °C min, rapid cool.

What is the Chinese (GB) equivalent of ASTM A403 WP310S?

The nearest Chinese equivalent is S31008 (06Cr25Ni20), formerly 0Cr25Ni20. Equivalents are close but not identical — compare chemistry and properties before substituting.

What is the JIS equivalent of ASTM A403 WP310S?

The nearest Japanese (JIS) equivalent is SUS310S.

Does Teshi Group supply ASTM A403 WP310S?

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.

Ready to build to spec?

Share your drawing, bill of materials or technical requirements with the Teshi team.