SS 321/321H Pipe Fittings


Reliable Pipes and Tubes Ltd. is a leading manufacturer and supplier of stainless steel 321 (1.4541) and 321H (1.4878) grade buttweld pipe fittings and flanges. RELIABLE PIPES & TUBES LTD. offers a complete range of stainless steel 321/321H pipe fittings such as SS 321 reducer, SS 321 elbow, SS 321 tee, SS 321 cross, SS 321 end caps, SS 321 stub ends and SS 321 pipe bends. Stainless steel 321 and 321H pipe fittings are manufactured in compliance with ASTM A-403 and ANSI B16.9 / 16.28/ MSS SP-43 / Welding Bevel Standards ANSI B 16.25.

We specialise in the manufacture and supply of SS 321 pipe bends in both standard and non standard sizes, with bending radius of 1D to 10D or any other custom bending radius. We offer ex-stock delivery of various standard size and type SS 321 pipe fittings, SS 321 flanges and SS 321 pipe bends. Our specialty is to manufacture and supply large size fabricated 100% radiography tested SS 321 elbows, SS 321 reducers, SS 321 tees and SS 321 large diaReliable Pipes and Tubes fabricated pipes.

Stainless ASTM A403, ASTM A182, ASTM A240 – 321/321H PIPE FITTINGS, SS 321/321H FLANGES SUPPLIER

stainless steel 321/321H pipe fittings
SS 321/321H Pipe Fittings
stainless steel 321/321H pipe flanges
SS 321/321H Pipe Flanges
stainless steel 321/321H forged fittings
SS 321/321H Forged Fittings


Grade 321 is a common austenitic 18/8 stainless steel alloy, with the addition of titanium. Type 321 stainless steel is similar to Type 304 stainless steel but with a titanium addition of at least five times the carbon content. The major difference between them is that the titanium addition reduces carbide precipitation during welding.

Stainless steel 321 grade is widely used in high temperature environments of up to 900° C. 321 stainless steel has good welding and forming capabilities and is widely used in operating temperature environments in excess of 500° C. Stainless steel 321H, commonly referred as UNS S32109, is the higher carbon version of the 321 grade, to provide higher temperature strength.

RELIABLE PIPES & TUBES LTD. also stocks and supplies a complete range of SS 321 pipes to complement our existing production range of SS 321 buttweld fittings and SS 321 flanges. Stainless steel 321 seamless pipes can be supplied in cut to length sizes and also machined or fabricated to meet your custom piping requirements.

Stainless Steel Tradename UNS no. Werkstoff No. Density (g/cm3)
321 321 Stainless S32100 1.4541 7.92
321H 321H Stainless S32109 1.4878 7.92


SS 321/321H Pipe Fittings Production Range

Specification ASTM A182 / A403 & ASME SA182 / SA403
Type Seamless / Welded / Fabricated
Variants 321, 321H
Bending Radius R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom
Range ½”NB to 48″NB in Sch 10s, 40s, 80s, 160s, XXS.
Dimensions ANSI/ASME B16.9, B16.28, MSS-SP-43.


Buttweld Stainless Steel 321/321H Pipe Fittings

Seamless/Welded 100% Radiography Tested

Products Size
SS 321 Elbows – Long Radius SS 321/321H Stub Ends Sizes 1/2″ – 48″
SS 321/321H Elbows – Short Radius SS 321H Crosses
SS 321H Reducing Elbows SS 321 Reducing Crosses
SS 321 45° Elbows SS 321/321H 180° LR Return Bends
SS 321 Tees SS 321H 180° SR Return Bends
SS 321H Equal Tees SS 321/321H Pipe Bends / Piggable Bends
SS 321/321H Reducers SS 321 Couplings
SS 321H Concentric Reducers SS 321/321H Steel Pipe Nipples
SS 321 Eccentric Reducers SS 321H Forged/Plate Cut Rings
SS 321 3D Elbow SS 321/321H End Caps
SS 321/321H 5D Elbow SS 321 Forged / Plate Circles
SS 321/321H Pipe Fittings SS 321 Pipe Fittings


High Pressure Forged SS 321/321H Pipe Fittings

Threaded and Socket Weld Pipe Fittings

Products Size
SS 321/321H 90° Elbows SS 321/321H Couplings Sizes 1/8″ – 4″
Pressure Ratings –
2000 LBS, 3000 LBS, 6000 LBS, 9000 LBS
SS 321 45° Elbows SS 321H Reducers
SS 321H Street Elbows SS 321/321H Inserts
SS 321/321H Tees SS 321 Caps
SS 321H Crosses SS 321/321H Unions


SS 321/321H Flanges

SS 321/321H Forged and Plate Flanges

Specification ASTM A182 / A240 & ASME SA182 / SA240
Grade 321 (1% Ni), 321H (4% Ni)
Standard ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc.
Size 1/8″ to 36"
Dimensions ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc.
Class / Pressure 150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.


Product Size
SS 321/321H Slip-On Flanges SS 321H Threaded Flanges 1/8″ – 36″
Raised Face or Flat Face
SS 321 Weld Neck Flanges SS 321/321H Socket Weld Flanges
SS 321/321H Blind Flanges SS 321 Reducing Flanges
SS 321 Lap Joint Flanges SS 321H Plate Flanges