Stainless Steel Buttweld Fittings

Stainless Steel Buttweld Fittings

Stainless Steel Buttweld Fittings are defined as a part used in a piping system, for changing direction, branching or for change of pipe diameter, and which is mechanically joined to the system. Buttweld fittings is a butt-welded connected pipe fittings, it is easy for installation and maintenance. There are many different types of BW fittings and they are the same in dimensions and schedules as the pipe.

buttweld fittings

Buttweld fittings (BW fittings) whose dimensions, dimensional tolerances et cetera are defined in the ASME B16.9 standards. Light-weight corrosion resistant fittings are made to MSS SP43. We also supply stainless steel butt weld fittings of ISO05251, EN10253-3, EN10253-4, GOST 17380/17378/17375/17376/17379, JIS etc.

Available Material for Buttweld Fittings:

  • Stainless Steel: A403 304/L, 304H 310S, 310H 316/L, 316Ti, 316H 317/L 321/H 347/H S31803 S32750 904L 254SMO (S31254)
  • Duplex & Super Duplex: A815 UNS S31803, S32205, UNS S32750, S32760
  • Nickel-base Alloy: Alloy 200, Monel 400, K500, Inconel 600, 625, Incoloy 800, 800H, 800HT, 825, alloy 20, alloy28, hastelloy C22, C276 etc.
  • Copper-Nickle Alloy: Cu70Ni30(C71500, B30), Cu90Ni10(C70600,B10)
  • Titanium Alloy: Gr. 1, Gr.2, Gr.11 etc.
  • Carbon Steel: A234 WPB, WPC
  • Low Temperature Steel: A420 WPL3, WPL6
  • Alloy Steel: A234 WP5, WP9, WP11, WP12, WP22, WP91,WP911,WPR
  • High Yield Steel: ASTM A860 WPHY42, 46, 50, 52, 56, 60, 65, 70


  • ASME/ANSI B16.9,kaysuns bw fittings-2
  • ASME/ANSI B16.28,
  • MSS-SP-43,
  • MSS-SP-75,
  • BS 1640,
  • DIN/EN10253,
  • JIS B2311/2312/2313,
  • ISO 3419,
  • ISO 5251,
  • GOST etc.


  • Size: 1/8'' to 104'', SCH5S~SCH160
  • Connection End: Butt-welded.
Product Size* Wall Thickness** Seamless Welded
Elbow 1/2"-24" SCH10S~XXS
8"-104" SCH5S~80S/XS
Tee 1/2"-24" SCH10S~XXS
8"-104" SCH5S~80S/XS
Reducer 1/2"-24" SCH10S~XXS
8"-104" SCH5S~80S/XS
Cap 1/2"-80" SCH10S~SCH160
Lap Joint Stub End 1/2"-24" SCH5S~80S/XS
8"-80" SCH5S~80S/XS


* Dimension range is not available for some special grade such C276-16"*SCH160. Please make a specific inquiry for these materials.

**Wall thickness range is not available for duplex and some special grade, please make a specific enquiry

Strength of Our Stainless Steel Buttweld Fittings:

  • Material of stainless steel buttweld fittings are from reputed mill to guarantee the chemical composition and mechanical properties. Material certificate will be submitted follow to orders.
  • Heat Treatment of solution annealing for the tube and fittings are available. The heat treated will be relief stress which caused by cold forming of fabrication, to improve the corrosion performance.
  • Fast delivery is possible to meet your needs well in time.
  • Low cost from bulk production will reduce your budget and improve your business.
  • Small quantity available.
  • Customized fabrication to client’s design,sample.
  • Material certificate is traceability.

Quality & Inspection:

  • PMI test to verify material grade
  • Dimension controlling during fabricating and finished
  • Visual and surface 100% examination before shipment
  • End protected for shipment
  • Packed in carton box firstly, then in wooden case

Surface Finish:

Outside and Inner surface can be treated complied to specified needs for stainless steel, duplex stainless and nickled-based alloy.

  • Pickled, Bright, Poilishing etc
  • Both outside and inner available.


  • Ship building,
  • Petrochemical,
  • Steel plant,
  • Refineries,
  • Chemical,
  • Fertilizers,buttwelded fittings
  • Defence,
  • Power plant,
  • Shipyard,
  • Oil & gas,
  • Offshore,
  • Railway,
  • LNG,
  • etc.

Angularity Tolerance of  Buttweld Fittings ASME B16.9

Nominal Size DN 15-100 125-200 250-300 350-400 450-600 650-750 800-1050 1100-1200 1300-1500
NPS 1/2 - 4 5-8 10-12 14-16 18-24 26-30 32-42 44-48 52-60
Off Angle Q 1 2 3 3 4 5 5 5 6.4
Off Plain P 2 4 5 6 10 10 13 19 20

*For more information of buttweld fittings, please feel free to contact us.

Buttweld Fittings Catalog

Stainless Steel Buttwelded Fittings Dimension