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Austenitic stainlessOEM manufacturerFlanges · forged fittings · butt weld fittings

Austenitic Stainless Steel Flanges & Fittings — 304L to 310S

Austenitic stainless steels are the everyday choice for corrosive process lines, with grades tuned for low carbon (L), molybdenum for chlorides (316, 317L), stabilisation for high temperature (321, 347) and oxidation resistance (310).

Teshi Group manufactures stainless steel flanges to ASTM A182 and butt weld fittings to ASTM A403 in all common grades, dual-certified where the chemistry allows.

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Austenitic stainless — grades, chemistry and properties

Grades and ASTM / ASME specifications

Grades and ASTM / ASME specifications
GradeForged flanges & fittingsButt weld fittingsPlatePipe
304 / 304LUNS S30400 / S30403 · W.Nr. 1.4301 / 1.4306ASTM A182 F304 / F304LASTM A403 WP304 / WP304LASTM A240ASTM A312
316 / 316LUNS S31600 / S31603 · W.Nr. 1.4401 / 1.4404ASTM A182 F316 / F316LASTM A403 WP316 / WP316LASTM A240ASTM A312
317LUNS S31703 · W.Nr. 1.4438ASTM A182 F317LASTM A403 WP317LASTM A240ASTM A312
321 / 321HUNS S32100 / S32109 · W.Nr. 1.4541ASTM A182 F321 / F321HASTM A403 WP321ASTM A240ASTM A312
347 / 347HUNS S34700 / S34709 · W.Nr. 1.4550ASTM A182 F347 / F347HASTM A403 WP347ASTM A240ASTM A312
310 / 310SUNS S31000 / S31008 · W.Nr. 1.4845ASTM A182 F310ASTM A403 WP310SASTM A240ASTM A312

Chemical composition (weight %, maximum unless a range is given)

Chemical composition (weight %, maximum unless a range is given)
GradeCMnSiCrNiMoNbTi
304 / 304L0.08 / 0.0302.001.0018.0–20.08.0–11.0 / 8.0–12.0———
316 / 316L0.08 / 0.0302.001.0016.0–18.010.0–14.02.00–3.00——
317L0.0302.001.0018.0–20.011.0–15.03.0–4.0——
321 / 321H0.082.001.0017.0–19.09.0–12.0——5×(C+N) – 0.70
347 / 347H0.082.001.0017.0–20.09.0–13.0—10×C – 1.10—
310 / 310S0.25 / 0.082.001.00–1.5024.0–26.019.0–22.0———

Mechanical properties (minimum, room temperature)

Mechanical properties (minimum, room temperature)
GradeTensile strengthYield strength (0.2 %)ElongationNote
304 / 304L515 MPa (75 ksi)205 MPa (30 ksi)30 %304L: 485 / 170 MPa
316 / 316L515 MPa (75 ksi)205 MPa (30 ksi)30 %316L: 485 / 170 MPa
317L———Higher Mo for pitting
321 / 321H515 MPa (75 ksi)205 MPa (30 ksi)30 %Ti-stabilised
347 / 347H515 MPa (75 ksi)205 MPa (30 ksi)30 %Nb-stabilised
310 / 310S515 MPa (75 ksi)205 MPa (30 ksi)30 %Oxidation resistant

Values are minimums and limits from the governing ASTM / ASME specifications, summarised for convenience. The current edition of the specification takes precedence; confirm requirements against your project specification.

Where it is used

  • Chemical, fertiliser and pharmaceutical process piping
  • Food, water and utility lines
  • Refinery hydrotreater and high-temperature lines (321, 347)
  • Furnace and kiln piping (310S)
  • Cryogenic service

Testing & certification

  • Solution annealed
  • Intergranular corrosion test to ASTM A262 Practice E when specified
  • PMI and dimensional inspection
  • EN 10204 3.1 certificate

Austenitic stainless products we manufacture

All products
Weld Neck Flanges01OEM manufacturer

Weld Neck Flanges

ASME B16.5 · ASME B16.47

Blind Flanges02OEM manufacturer

Blind Flanges

ASME B16.5 · ASME B16.47

Slip-On Flanges03OEM manufacturer

Slip-On Flanges

ASME B16.5 · EN 1092-1 Type 12

Butt Weld Elbows04OEM manufacturer

Butt Weld Elbows

ASME B16.9 · ASME B16.25

Butt Weld Tees05OEM manufacturer

Butt Weld Tees

ASME B16.9 · ASME B16.25

Weldolets & Sockolets06OEM manufacturer

Weldolets & Sockolets

MSS SP-97 · ASME B16.11

Industries and projects

Industry

Chemical & Petrochemical

Where Austenitic stainless is specified

ViewIndustry

Refining

Where Austenitic stainless is specified

ViewIndustry

Water Treatment & Desalination

Where Austenitic stainless is specified

ViewProjects

Mega-projects & EPC supply

Project BOQs, shutdowns and annual rate contracts

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Grade data sheets

ASTM A182 F304ASTM A182 F304LASTM A182 F316ASTM A182 F316LASTM A182 F321ASTM A403 WP316L

Other materials

904L & 254 SMODuplex 2205Super DuplexTitaniumInconelHastelloy, Monel & Alloy 20Copper-NickelChrome-moly alloy steelCarbon & low-temp steel

Austenitic stainless by product

SS 304 / 304L flangesSS 316 / 316L flangesSS 321 / 347 flangesSS 304 / 304L pipe fittingsSS 316 / 316L pipe fittings

FAQ

Austenitic stainless: common questions

What does the L in 304L and 316L mean?

L grades have carbon limited to 0.030 % to avoid chromium carbide precipitation during welding, which protects the weld zone from intergranular corrosion.

When should 321 or 347 be used instead of 304L?

321 (titanium-stabilised) and 347 (niobium-stabilised) resist sensitisation during long service at roughly 425–850 °C, so they are used in refinery hydrotreaters and high-temperature lines.

Can flanges be dual certified 316/316L?

Yes. When the chemistry meets the low-carbon limit and the mechanical properties meet the higher 316 values, flanges are certified to both F316 and F316L.

Which standard covers stainless butt weld fittings?

ASTM A403 covers wrought austenitic stainless steel fittings (WP grades), with dimensions to ASME B16.9 and B16.28.

Austenitic stainless steel grade data sheets

Austenitic stainless steel overview →

Chemical composition, mechanical properties and PDF data sheet for each grade.

ASTM A182 F304ASTM A182 F304LASTM A182 F316ASTM A182 F316LASTM A182 F321ASTM A312 TP304ASTM A312 TP304LASTM A312 TP316ASTM A312 TP316LASTM A403 WP304ASTM A403 WP304LASTM A403 WP316ASTM A403 WP316LASTM A351 CF8MASTM A182 F304HASTM A182 F316HASTM A182 F316TiASTM A182 F317LASTM A182 F310ASTM A182 F321HASTM A182 F347ASTM A182 F347HASTM A312 TP304HASTM A312 TP316HASTM A312 TP321ASTM A312 TP347ASTM A312 TP310SASTM A312 TP317LASTM A403 WP321ASTM A403 WP347ASTM A403 WP310SASTM A403 WP317LASTM A351 CF8ASTM A351 CF3M

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