ASTM A182 Forged Stainless and Alloy Flanges, Fittings and Valve Parts

What ASTM A182 Covers

A182 governs forgings and rolled bar converted into finished pressure components: weld-neck, slip-on, socket-weld, lap-joint, threaded and blind flanges; socket-weld and threaded forged fittings; and valve bodies, bonnets and other pressure-retaining parts. It spans two broad material families in one specification, the ferritic and martensitic low-alloy chrome-moly steels and the austenitic stainless and super-austenitic grades, each identified by an "F" prefix designation.

Because A182 defines the material rather than the dimensions, it is almost always paired with a dimensional standard. Flange faces, bores and bolt circles come from ASME B16.5 for classes 150 through 2500, while socket-weld and threaded fitting geometry comes from ASME B16.11. The A182 grade sets the metal; the B16 standard sets the shape.

A182 Grade Designations

The "F" number ties each forged grade back to a familiar wrought grade. The table below lists the common austenitic and chrome-moly A182 grades Nandini Steel supplies and the mill grade each one corresponds to.

Choosing the Right Grade

The "L" low-carbon variants, F304L and F316L, carry carbon at or below 0.03%, which keeps the heat-affected zone free of chromium-carbide precipitation during welding and avoids sensitization. For components held for long periods in the 425–815 °C range, the stabilized grades F321 and F347 lock up carbon with titanium or niobium and resist intergranular corrosion without a post-weld anneal.

When the medium is hot concentrated chloride or sulfuric acid, the austenitic grades reach their limit and 904L is the economical answer. Its copper-bearing, roughly 4.5% molybdenum chemistry gives a PREN near 34, well above the ~24 of 316 and ~18 of 304, so F904L flanges hold up where F316 would pit. The chrome-moly F11, F22 and F91 grades sit on the opposite side of the catalog, selected for creep strength in elevated-temperature alloy-steel piping rather than corrosion.

Heat Treatment and Testing

Every A182 forging is supplied in a defined heat-treated condition. Austenitic grades are solution annealed and quenched so the microstructure is fully austenitic and carbides are in solution; the chrome-moly grades are normalized and tempered, or annealed, to develop their mechanical properties. The specification sets minimum tensile and yield strength, elongation and hardness for each grade, and the mill verifies them on test specimens cut from the production forgings or their representative blanks.

For austenitic forgings destined for corrosive duty, an intergranular corrosion test per ASTM A262 can be specified on the order to confirm the material is not susceptible to weld decay. In sour oil and gas service, the hardness and condition limits of NACE MR0175 / ISO 15156 should be called out on the purchase order so the heat is supplied qualified.

Where A182 Fits Among Piping Standards

A182 is the forged-component member of a connected family of piping specifications. Matching A182 flanges and forged fittings to the right pipe and buttweld fittings keeps an entire line within one metallurgical pedigree.

For the chrome-moly side, the F11, F22 and F91 flange grades run alongside ASTM A335 seamless chrome-moly pipe and ASTM A387 plate, giving a complete elevated-temperature piping system.

A182 at Nandini Steel

Nandini Steel is an ISO 9001:2015-certified stockist and supplier of stainless, nickel-alloy and alloy-steel piping products, established in 2003 and based in Mumbai. We hold A182 forged flanges and forged fittings in the common F304/F304L, F316/F316L, F321, F347 and F904L grades, along with the chrome-moly F11, F22 and F91 designations, as part of our stainless steel flange and forged-fitting ranges.

Everything is ex-stock and available for immediate dispatch, and every order ships with an EN 10204 3.1 or 3.2 mill test certificate so the heat, chemistry, mechanicals and heat-treat condition are fully traceable. As a certified specialist in 904L and the high-nickel alloys, we can supply F904L forgings for sulfuric-acid and high-chloride duty where standard austenitic grades fall short. These components serve oil and gas, petrochemical and chemical processing plants across more than 36 export countries.

Frequently Asked Questions

Request a Quote

For live pricing and stock availability on ASTM A182 forged flanges, fittings and valve parts, contact Nandini Steel at reachus@nandinisteel.com, call +91 22 43404600, or message WhatsApp +91 99202 09184 with your grade, size and class.