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AISI 321H Stainless Steel Pipe Flange Supplier

We are stockists and suppliers of Stainless Steel 321H Flanges and Fittings.
Other Names: ASTM A182 F321H, Stainless Steel Flanges, 321H ss Pipe Flanges, ss321H Flanges
Material: SS321H, AISI 321H, SUS321H, INOX 321H, Stainless Steel 321H
Brand: Siddhagiri Metals and Tubes
Manufacturer: Siddhagiri Metals and Tubes
Rating: 4.1/5 based on 76 customer reviews

AISI 321H Stainless Steel Pipe Flanges Supplier • ASTM A182 F321H • Stainless Steel Flanges

Siddhagiri Metals and Tubes is an ISO 9001:2015 certified supplier of AISI 321H Flanges as per ASTM A182 F321H specification in PN6 to PN160 pressure ratings.

A flange joint is a connection of pipes, where the connecting pieces have flanges by which the parts are bolted together. The principle of a flange is to apply a mechanical force by using bolts to preload the gasket until contact stress between flanges and gasket is sufficient to maintain a seal. Connection to the pipe is by welding or threading. To allow easy functionality and inter-changeability, these ASTM A182 /ASME SA182 Flanges are designed to have standardised dimensions which include ANSI, ASME, DIN, EN, BS, JIS. Flanges have major applications in Oil, Gas, Petrochemical, Ship-Building, Marine, Food, Dairy, Railways and other associated industries were piping systems are required.

Stainless Steel Slip On Flange — Stainless Steel Slip-On Flanges is slightly larger than the outer diameter of the pipe it is to be used with. The pipe is slipped into the Flange prior to welding both inside and outside. We supply a wide range of slip-On Flanges in different dimensions and sizes. SS 321H Slip On Flange and Stainless Steel Slip On Flange is in ready stock with Siddhagiri Metals and Tubes.

Stainless Steel Blind Flange — Stainless Flange with no borehole are known as Blind Flange and used to close the end of the pipe. Blind Flanges are supplied as threaded or welded from class 150lb to 2500lb. SS 321H Blind Flange and Stainless Steel Blind Flange is in ready stock with Siddhagiri Metals and Tubes.

Stainless Steel Weld Neck Flange — Stainless Weld Neck Flanges are widely used in high-pressure piping systems and can be easily recognised by the long tapered hub. The size of the bore hole is usually equal to the size of the pipe. SS 321H Weld Neck Flange and Stainless Steel Weld Neck Flange is in ready stock with Siddhagiri Metals and Tubes.

Stainless Steel Socket Weld Flange — Initially developed for small high-pressure piping systems a Socket Weld Flange is similar to Slip On Flange. The flange is installed by welding around the hub of the flange. SS 321H Socket Weld Flange and Stainless Steel Socket Weld Flange is in ready stock with Siddhagiri Metals and Tubes.

Stainless Steel Threaded Flange — Threaded Flanges are used for special application where the flange can be assembled to the piping system by without welding. We specialise in all forms of threaded flanges and can supply it in multiple size range. SS 321H Threaded Flange and Stainless Steel Threaded Flange is in ready stock with Siddhagiri Metals and Tubes.

Stainless Steel Lap Joint Flange — Lap-Joint Flanges are similar to Slip-On flanges and are generally used with Lap-Joint Stubs. This type of flange is highly used where the piping systems are disassembled from time to time. SS 321H Lap Joint Flange and Stainless Steel Lap Joint Flange is in ready stock with Siddhagiri Metals and Tubes.

Siddhagiri Metals and Tubes supplies Stainless Steel Flanges in different sizes and pressure ratings. Our production stock of Stainless Steel Flanges includes size range from 1/2” to 24”, 26” to 60”, 1” to 24”, 1/2” to 24”, 12” to 60”, 26” to 48”, 21/16” to 30”, DN10 to DN3600. We have an inventory of flanges rating from Class 150 to 2500 Lbs, Class 300 to 2500 Lbs, Class 150 to 2500 Lbs, Class 150 to 900 Lbs, Class 150 to 600 Lbs, 2000 Psi to 20000 Psi, PN6 to PN 160. Our flanges conform to international dimension standards such as ASME / ANSI B16.5, ASME B16.47 / API 605, ASME / ANSI B16.36, ASME B16.48 / API 590, MSS-SP-44, BS 3293, API 6A and DIN. We stock various types of flanges which include Slip On Flange, Blind Flange, Weld Neck Flange, Socket Weld Flange, Threaded Flange, Lap Joint Flange.

Siddhagiri Metals and Tubes have an extensive inventory of multiple stainless steel flanges and alloy flanges to compliment our pipe products. Most of our high quality, flanges and gasket kits are ready to ship upon request. Speak to one of our specialists and find out which flanges to meet your flange and piping specifications. We have partnered with the best flange brands around the world to meet your flange requirements. Moreover, we are SAUDI ARAMCO approved supplier of flanges and provide all documents including Mill Certificate along with the shipment.

Our primary export destinations include Russia, Australia, UK, Germany, US, Saudi Arabia, Qatar, Jordan, South Africa, Thailand, Canada, Mexico, Brazil, UK and many more.

  • Flange Specification: UNS S32109, EN 1.4878, WNR 1.4878, SS 2337, ASTM A182 F321H
  • Dimension Standard: ASME / ANSI B16.5, ASME B16.47 / API 605, ASME B16.48 / API 590, MSS-SP-44, BS 3293, API 6A, DIN DN10 to DN3600
  • Size Range: 1/2” to 24”
  • Rating: Class 150 to 2500 Flanges | PN 6, PN 10, PN 16, PN 25, PN 40, PN 64 upto PN 160
  • Type of Flanges: Stainless Steel Weld-Neck Flanges, Stainless Steel Socket-Weld Flange, Stainless Steel Lap-Joint Flange, Stainless Steel Orifice Flange, Stainless Steel Tongue-Grove Flange, Stainless Steel Blind Flange, Stainless Steel Threaded Flange, Stainless Steel Slip-On Flange, Stainless Steel Spectacle Flange, Stainless Steel Plate Flanges
  • Form: SORF, BLRF, WNRF, SWRF, LJRF, LWNRF, RTJ, Flat Face, Ring Type, Raised Face
  • Origin: Indian Origin, European Origin, Japanese Origin
  • Testing and Documents: Mill Test Certificates, EN 10204 3.1, Chemical Reports, Mechanical Reports, Destructive Test Report, Non Destructive Test Reports, PMI Test Reports, Visual Inspection Reports, Third Party Inspection Reports, NABL Approved Lab Reports
  • Packing: Packed in Wooden Boxes, Bubble wraps, Steel Strips Bundled, or as per Customers Requests

AISI 321H Flanges in Stock

Dimension Standard Size Range Rating
ASME / ANSI B16.5 Flanges 1/2” to 24” Class 150 to 2500 Lbs
ASME B16.47 / API 605 Flanges 26” to 60” -
ASME / ANSI B16.36 Flanges 1” to 24” Class 300 to 2500 Lbs
ASME B16.48 / API 590 Flanges 1/2” to 24” Class 150 to 2500 Lbs
MSS-SP-44 Flanges 12” to 60” Class 150 to 900 Lbs
BS 3293 Flanges 26” to 48” Class 150 to 600 Lbs
API 6A Flanges 2 1/16” to 30” 2000 Psi to 20000 Psi
DIN Flanges DN10 to DN3600 PN6 to PN 160

Forms of SS321H Flanges with ASTM A182 F321H in Stock

In Stock Stainless Steel Weld Neck Flanges Manufacturer

SS 321H Weld Neck Flange

321HSS Weld Neck Flange available from class 150 to 2500

In Stock Stainless Steel Tongue Groove Flanges Manufacturer

SS 321H Tongue Groove Flange

321HSS Tongue Groove Flanges available from PN6 to PN 160 ratings

In Stock Stainless Steel Threaded Flanges with ASME B16.5 and ANSI B16.5 Manufacturer

SS 321H Threaded Flange

321HSS Threaded Flange available in ASME / ANSI B16.5 standards

In Stock Stainless Steel Spectacle Flanges Manufacturer

SS 321H Spectacle Flange

321HSS Spectacle Flange with ASTM A182 /ASME SA182

In Stock Stainless Steel Socket Weld Flanges Manufacturer

SS 321H Socket Weld Flange

321HSS Socket Weld Flangewith ASTM A182 /ASME SA182

In Stock Stainless Steel Slip On Flanges Manufacturer

SS 321H Slip On Flange

321HSS Slip On Flange ASTM A182 /ASME SA182

In Stock Stainless Steel Orifice Flanges Manufacturer

SS 321H Orifice Flange

321HSS Orifice Flange available from PN6 to PN 160 ratings

In Stock Stainless Steel Lap Joint Flanges with ASME B16.36 Manufacturer

SS 321H Lap Joint Flange

321HSS Lap Joint Flange available in ASME B16.36 and ANSI B16.36 ASTM A182 /ASME SA182 Flanges

In Stock Stainless Steel Blind Flanges Manufacturer

SS 321H Blind Flange

321HSS Blind Flange available from class 150 to 2500LB

  • Chemical Properties
  • Mechanical Properties
  • Physical Properties
  • C Mn P S Si Cr Ni Ti
    MIN 0.040 - - - - 17.000 9.000 -
    MAX 0.100 2.000 0.045 0.030 0.750 19.000 12.000 0.700
  • Yield Strength
    0.2% Proof
    Tensile strength
    (% in 50mm)
    MIN 205 515 40.00  
    MAX       95
  • Density kg/dm³ 7.76
    Young's Modulus GPa 196
    Thermal Conductivity W/m•°C 11.9
    Heat Capacity J/kg•°C 472
    Electrical Resistivity µΩm 0.96

Properties of AISI 321H Stainless Steel

Type 321 Cold Forming

Type 321 is easliy cold formed due to its ductile nature.

Type 321 Hot Forming

Type 321 can be readily formed and drawn.

Type 321 Machining

Type 321 is less machineable than Type 410 Stainless Steel.

Type 321 Welding

Type 321 is easily weldable by all standard techniques. No post weld treatment is required.

Type 321 Heat Treatment

Type 321 is non-hardenable by heat treatment. 321 is annealed by heating it to 1750 – 2050 °F (954 – 1121°C), then water quench or air cool.

Services We Offer


Documentation is a very important part of the products we supply, and we work continuously to enhance the efficiency of the document-handling process without compromising quality of the product. Documents provided along with the shipment include Certificate of Origin, Material Test Certificate as per EN 10204 3.1 and 10204 3.2, NACE MR10103 and NACE MR0175 certified Test Certificates.

Quality Assurance

Stainless Steel Flanges and Fittings are manufactured and controlled to international standards such as ASTM, ASME, BS, MSS, EN, DIN or WERKSTOFFE. Our products undergo stringent quality tests before they are dispatched.

Material Testing

PMI Testing, Ultrasonic Test, Mechanical Testing, Spectro Tests for Chemical Analysis of the grade, Flaring Test, IGC, etc. are some of the tests conducted at our facility. We welcome stage wise inspection from any of your representative or third party inspection agencies.

Packing and Delivery

The product is wrapped and packed in wooden crates or carton boxes. Our primary goal is to deliver quality products in time, no matter where the client is located.

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