ASTM A182 is the specification that governs forged and rolled alloy-steel piping components — flanges, fittings, valve bodies, and similar hardware — rather than straight pipe. Because these parts are forged and machined to shape (not rolled to a bore like seamless pipe), A182 covers a wide family of grades spanning plain carbon-moly through high-chromium stainless compositions. This page covers Grade F22, a 2.25% chromium, 1% molybdenum low-alloy steel.

F22 is one of the classic chrome-moly grades used where a piping system runs hot and under pressure for extended periods — refinery hydroprocessing units, high-temperature steam and reheat lines, and other elevated-temperature service where plain carbon steel starts to lose creep strength. The chromium and molybdenum content raises high-temperature strength and improves resistance to hydrogen attack compared with carbon-moly grades, which is why F22 flanges and fittings show up heavily in refinery process piping. It's typically supplied normalized and tempered or quenched and tempered, giving a minimum tensile strength of 415 MPa (60,000 psi) and minimum yield of 205 MPa (30,000 psi) in the standard (Class 1) condition — normalized-and-tempered Class 3 material carries higher minimums.

F22 machines noticeably differently than a plain carbon pipe steel. The 2.25% chromium and 1% molybdenum content forms fine alloy carbides that raise abrasive wear on the cutting edge, and the normalized-and-tempered condition typically supplied gives it more strength and hardness to cut through than a low-carbon material. Cutting forces and heat generation at the tool-chip interface both run higher, so tool life — not surface finish — is usually the limiting factor on this grade.

Because A182 parts are forgings rather than round bar stock, the work is dominated by facing flange faces, boring valve body cavities, cutting bevels for welding, and machining bolt-circle features — often on thick, heavy sections with variable stock removal. That combination of interrupted engagement and abrasive alloy content calls for a coated carbide grade with both wear resistance and enough toughness to survive an uneven cut, rather than the sharpest, most fragile edge available.

Chip control is generally manageable on F22 — it doesn't have the gumminess of a low-carbon steel — but heat buildup from the alloy carbides means coolant delivery and a coating with good hot hardness matter more here than on carbon-moly grades. Matching insert geometry to the specific operation (rigid geometries for roughing forged surfaces, sharper edges for finish passes on bore and face features) makes the biggest difference in consistent tool life.