Alloy Steel Pipe Flanges — Quality & Variety

Alloy flanges are pipe flanges manufactured from steel alloys that contain additional elements — such as chromium, molybdenum, nickel, or manganese — beyond the base carbon content. These alloying elements enhance mechanical properties like tensile strength, toughness, hardness, and corrosion resistance. Common alloy steel grades used for flanges include ASTM A182 F11, F22, and F91, each suited to high-temperature or high-pressure service conditions in power generation, chemical processing, and similar industries.

The primary ASTM standard governing alloy steel flanges is ASTM A182, which covers forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves intended for high-temperature service. Within A182, different grades such as F11, F22, F5, and F91 define specific alloy compositions and mechanical property requirements. Dimensional standards for flanges are governed separately by ASME B16.5 for sizes up to 24 inches and ASME B16.47 for larger diameters.

MTS Forge manufactures alloy steel pipe flanges up to 14 inches in size. Each flange is produced under a rigorous Quality Assurance Program with complete traceability, making them suitable for demanding applications in commercial nuclear, power generation, aerospace, and defense sectors. For specific size or grade requirements outside this range, contact our team to discuss custom forging options.

MTS Forge supplies alloy steel pipe flanges to a broad range of industries including commercial nuclear, aerospace, defense, power generation, chemical processing, machine manufacturing, and gas and petroleum. The majority of current flange production supports the commercial nuclear sector, which requires the highest levels of quality assurance and material traceability in the industry.

MTS Forge's flange manufacturing is governed by a comprehensive Quality Assurance Program that encompasses Mil I 45208, NCA 3800, and Mil Q9858 certifications. These standards ensure rigorous process control, dimensional accuracy, and full material traceability from raw material through finished component — requirements that are mandatory for nuclear, defense, and aerospace procurement programs.

Yes. MTS Forge performs in-house normalizing heat treatment at its Coatesville, PA facility. This process heats forged flanges above their upper critical temperature and allows controlled cooling to refine grain structure, eliminate internal stresses, and produce uniform mechanical properties. The result is improved tensile strength, toughness, ductility, and machinability — essential qualities for alloy steel flanges in critical service environments.

Yes. MTS Forge specializes in custom forged components tailored to exact customer drawings and specifications. With a large inventory of tooling and in-house tooling design capability, the team can produce custom flange geometries efficiently and cost-effectively. Custom forgings are manufactured using time-honored craftsmanship combined with advanced technology, and all production is completed domestically at our Coatesville, Pennsylvania facility.

MTS Forge works with a wide range of materials for flange production, including alloy steels, stainless steels (such as 316-L), and high-performance alloys. The company's metallurgical expertise enables them to source and process materials appropriate for high-temperature, high-pressure, and corrosive service conditions. Specific grade availability can be confirmed with the MTS Forge team based on your application and dimensional requirements.