Stainless Steel 347/347H Flanges Manufacturer
Midland Alloys Inc., a reputable Indian manufacturer and international supplier of stainless steel flanges is known for producing precisely engineered goods that satisfy exacting industrial specifications. Our SS F347H and ASTM A182 stainless steel 347 flanges provide exceptional performance in high-stress and high temperature settings. These flanges are ideal for use at cryogenic as well as elevated temperatures due to their superior oxidation resistance and mechanical strength. Commonly used in boilers, heat exchangers, and exhaust systems, these flanges conform to ASME, ANSI, BS, DIN, and EN standards. According to ASTM A182 and A240 specifications, we produce stainless steel 347 seamless flanges and SS 347 forged flanges that are appropriate for high temperature and high pressure applications. Both structural and corrosion resistance requirement are satisfied by the SS UNS S34700 Flange and SS UNS S34709, 1.4961 Pipe Flanges. Due to their higher carbon content, our 347H variant flanges perform exceptionally well above 1000°F and provide improved creep resistance, making them appropriate for use in jet engine parts, chemical processing, and aircraft manifolds.
Benefits of SA182 F347 Pipe Flanges
Using stainless steel 347/347H flanges ensures long-term performance in aggressive and high-temperature environments.
- Perfect for boilers and exhaust systems it resists oxidation at high temperatures.
- retains a high creep strength in the face of extended heat and stress.
- During welding, niobium stabilization guarantees resistance to intergranular corrosion.
- Similar to 304 in terms of general corrosion resistance, but with additional stability at high temperatures
- Outstanding resilience against polythionic acid stress corrosion cracking in refinery environment maintains durability even in cryogenic setting.
- Weldable with little sensitization using standard methods (avoid oxyacetylene).
- Extremely adaptable utilized in chemical, power, refinery and aerospace industries
Stainless Steel 347/347H Flanges Specification
1/2" (15 NB) to 48" (1200NB)
ASTM A182 / A240 & ASME SA182 / SA240
ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc.
Threaded / Screwed / Forged / Plate
150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.
Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
Forging, Rolling, Casting
FNPT, NPT, BSPT, MNPT, BSPP
Contact us today to discuss how Stainless Steel 347/347H Flanges can benefit your application. Whether you need guidance in selecting the right pipes or have specific requirements, our team of experts is here to help you find the optimal solution.
Technical Details & Delivery Condition
| Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
| BS | En | No | Name | ||||
| 347 | S34700 | – | X6CrNiNb18-10 | 1.4550 | – | – | – |
| 347H | S34709 | – | – | 1.4961 | – | – | – |
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | |
| 347 | min. | – | – | – | – | – | 17.0 | 2.00 | 9.0 | – |
| max. | 0.08 | 2.0 | 1.00 | 0.045 | 0.030 | 20.0 | 3.00 | 13.0 | – | |
| 347H | min. | 0.04 | – | – | – | – | 17.0 | 3.00 | 9.0 | – |
| max. | 0.10 | 2.0 | 1.00 | 0.045 | 0.030 | 19.0 | 4.00 | 13.0 | – | |
| Yield Strength 0.2% Offset |
Ultimate Tensile Strength |
Elongation in 2 in. |
Hardness | ||
|---|---|---|---|---|---|
| psi (min.) | (MPa) | psi (min.) | (MPa) | % (min.) | (max.) |
| 30,000 | 205 | 75,000 | 515 | 40 | 201 Brinell |
Stainless Steel Flanges Grades We Offer
Difference Between Stainless Steel 347/347H Flanges and Stainless Steel 304 Flanges
The primary distinction between 304 and 347 stainless steel flanges lies in their alloy composition and temperature stability. While both are austenitic grades, 347 stainless steel includes columbium (niobium) and tantalum, enhancing stability and corrosion resistance at elevated temperatures. This makes ASTM A182 F347 Flanges more suitable for thermal cycling and welding-heavy operations where intergranular corrosion is a concern. The high-temperature resistance needed in harsher service conditions is absent from 304 flanges, in contrast despite their good performance in ambient condition.
Plate
Shear
Press
Inspection
Lathe
Drilling
Cleaning
Flange
Inspection
Analytic
Marking
Packing & Shipping
Applications of SS DIN 1.4961 Flange
SS 347/347H flanges are widely used across industries that demand superior thermal and corrosion resistance. In chemical processing, they serve in corrosive fluid transport systems and reactors. In petroleum refining, they operate efficiently in units handling high heat and chemical exposure. The aerospace sector uses these flanges in aircraft exhaust components and jet manifolds due to their excellent thermal fatigue resistance. These flanges provide corrosion protection and mechanical integrity in heat exchangers. Boilers, superheaters and other pressure bound equipment exposed to high temperature gradients depend on ASME SA-182 SS 347 flanges in the power generation sector.
Why Choose Us for ASME SA‑182 SS 347 Flanges?
Midland Alloys Inc., a top producer and exporter of premium Stainless Steel 347/347H Flanges from India, is dedicated to material excellence and precision engineering. Using ISO-certified procedures, our manufacturing closely complies with ASTM, ASME and EN standards. We provide complete customization to match your precise requirements, including cut-to-length, machined end finishes, irregular schedules, and surface treatments. We serve customers in the Gulf, Europe, Africa, and Southeast Asia as a reputable manufacturer and exporter of stainless steel 347 flanges. Every product is tested internally, and upon request, we offer mill test certificates (MTC) with third-party inspections. We ensure timely delivery, project-specific logistics, and reliable handling of both small and bulk orders. We are dedicated to a long term collaboration supported by reliable quality control and satisfied customers. Every flange is marked in accordance with ASTM/ASME codes (such as ASTM A182 and ASME SA182) and comes with MTC attesting to its complete adherence to mechanical and chemical standard.
FAQs
The measurements adhere to ASME B16.47 for larger sizes and ANSI B16.5 for sizes up to 24 inches.
347H has higher carbon content than 347, offering better creep resistance above 1000°F.
SS 347 flanges price per kg varies by size, schedule, and finish—contact us for the latest rates.
