A182 304H Flange Equivalent and Ratings

A182 304H: Flange Equivalent and Ratings

At Gangsteel, a leading manufacturer and exporter of stainless steel products, we supply high-quality A182 304H forged stainless steel flanges compliant with ASTM A182 and ASME SA 182 standards. A182 304H, also known as F304H or AISI 304H, is a high-carbon austenitic stainless steel optimized for high-temperature forging applications up to 1500°F (815°C). This guide details the flange equivalents, specifications, ratings, and applications of A182 304H. Contact us at admin@gangsteel.com or explore our ASME SA240 Stainless sheet offerings.

Overview of A182 304H Forging

A182 304H is specified under ASTM A182 for stainless steel forged or rolled pipe flanges, forged fittings, valves, and parts for high-temperature service. As the forging equivalent to SA 240 GR 304H plates, it features high carbon (0.04-0.10%) for enhanced creep and rupture strength. Non-magnetic with a density of 8.00 g/cm³, A182 304H flanges are forged at 1800-2200°F (982-1204°C) for components like flanges and elbows in boilers and heat exchangers. See sa240 gr 304h for plate equivalents.

Chemical Composition

The chemical composition of A182 304H ensures high-temperature forging performance:

High carbon (0.04-0.10%) boosts creep resistance. See sa240 gr 304l for low-carbon variants.

Mechanical Properties

High strength at high temperatures (25.5 ksi allowable at 1000°F). See sa240 gr 304.

Physical Properties

• Density: 8.00 g/cm³.
• Melting Point: 1400-1450°C.
• Thermal Conductivity: 16.2 W/m·K.
• Coefficient of Thermal Expansion: 17.2 × 10⁻⁶/K.
• Max Service Temperature: 1500°F (815°C) continuous.

Corrosion Resistance

A182 304H resists mild acids and atmospheric conditions, outperforming SS204 vs SS 304. Higher carbon risks sensitization in forged welds; anneal for protection. See sa240 gr 316l for chlorides.

Weldability

Fair with ER308H fillers; low heat input (<2.0 kJ/mm) and annealing required for forged components. See sa240 gr 321.

Applications of A182 304H Flanges

A182 304H flanges are used in:

• High-temperature piping systems (weld neck, slip-on).
• Pressure vessel connections.
• Boiler flanges.
• Heat exchanger fittings.

For cost-effective options, see sa240 gr 201.

Pressure Ratings for A182 304H Flanges

A182 304H flanges are rated per ASME B16.5 for high-temperature service:

Ratings decrease with temperature; allowable stress 25.5 ksi at 1000°F. For Class 150-1500 flanges, see B16.5.

Pricing and Availability

As of October 19, 2025, A182 304H flange prices (Class 150, 1-4" NPS) range from $2.00-$5.00/kg. Gangsteel offers $2.00/kg FOB (MOQ 1 ton) for sa240 gr 304h. Contact admin@gangsteel.com or visit astm a 240 stainless plate.

FAQ on A182 304H Flange Equivalents

What is the chemical equivalence between A182 304H flanges and SA 240 GR 304H plate?

Identical: 0.04-0.10% C, 18-20% Cr, 8-10.5% Ni, ensuring high-temperature compatibility.

How do mechanical properties differ between A182 304H flanges and SA 240 GR 304H plate?

They are the same: tensile strength 515 MPa (75 ksi), yield strength 205 MPa (30 ksi), elongation 30%.

What are the physical properties of A182 304H flanges equivalent to SA 240 plate?

Density 8.00 g/cm³, melting point 1400-1450°C, max service temperature 1500°F (815°C) continuous.

What applications use A182 304H flanges as equivalent to SA 240 GR 304H plate?

High-temperature piping connections, boiler flanges, and heat exchanger fittings for pressure vessels.

Why choose Gangsteel for A182 304H flanges or SA 240 GR 304H plate?

Competitive pricing ($2.00/kg FOB for flanges, $1.60/kg for plate), 600+ ton stock, custom fabrication, and full certifications.