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Austenitic SSWrought butt-weld fittingsTG-MG-064 · Rev. 1 · October 2026

ASTM A403 WP317L — Chemical Composition & Mechanical Properties

ASTM A403 WP317L is a austenitic stainless steel grade for wrought butt-weld fittings (UNS S31703, EN / W.Nr 1.4438). 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 WP317L at a glance

SpecificationASTM A403 WP317L
Material familyAustenitic stainless steel
Product formWrought butt-weld fittings
UNS numberS31703
EN / W.Nr equivalent1.4438
Also known as317L
PREN (min values)27.9
DocumentTG-MG-064 · Rev. 1 · October 2026

Typical service

Butt-weld fittings for FGD and acid service

Heat treatment

Solution annealed 1040 °C min, rapid cool

Chemical composition of ASTM A403 WP317L (weight %)

C0.030 max
Mn2.00 max
P0.045 max
S0.030 max
Si1.00 max
Cr18.0–20.0
Ni11.0–15.0
Mo3.0–4.0

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 WP317L

All equivalents
Standard systemNearest equivalent grade
USA — ASTM / ASMEASTM A403 WP317L · ASME SA-403 WP317L
USA — UNSS31703
Europe — EN designationX2CrNiMo18-15-4
Europe — W.Nr1.4438
Japan — JISSUS317L
China — GB / NBS31703 (022Cr19Ni13Mo3)
China — old GB designation00Cr19Ni13Mo3
UK — BS (withdrawn)317S12

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 F317L
Seamless & welded pipeASTM A312 TP317L

FAQ

ASTM A403 WP317L: common questions

What is the minimum yield strength of ASTM A403 WP317L?

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

What is the carbon content of ASTM A403 WP317L?

0.030 max %.

What is the PREN of ASTM A403 WP317L?

About 28, 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 WP317L?

UNS S31703; the nearest European designation is W.Nr 1.4438. Equivalents are close but not identical — check the specification if substituting.

How is ASTM A403 WP317L heat treated?

Solution annealed 1040 °C min, rapid cool.

What is the Chinese (GB) equivalent of ASTM A403 WP317L?

The nearest Chinese equivalent is S31703 (022Cr19Ni13Mo3), formerly 00Cr19Ni13Mo3. Equivalents are close but not identical — compare chemistry and properties before substituting.

What is the JIS equivalent of ASTM A403 WP317L?

The nearest Japanese (JIS) equivalent is SUS317L.

Does Teshi Group supply ASTM A403 WP317L?

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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