Flanges are available various materials such as carbon steel, austenitic / martensitic / ferritic / duplex stainless steel, cast iron, aluminum, brass, bronze, plastic, etc. For specific services, flanges may be internally lined with protective materials (as pipes and fittings) or even painted externally. The material grade of Steel Flanges shall match the material grade of the joined pipes.

The most common materials for flanges are:

• Carbon steel
  • ASTM A 105 / A 266 Gr. 2 (high temperature carbon steel)
  • ASTM A350 LF1 to LF3 (low temperature carbon steel)
  • ASTM A694 Gr. F42 / F52 / F56 / F60 / F65 (high yield carbon Steel Flange to match API 5L linepipes)
    
• Alloy Steel
  • ASTM A182 Gr. F1 / F2 / F5 / F9 / F11 Cl. 2 / F12 Cl. 2 / F22 Cl. 3 / F91 (alloy steel flanges)
    
• Stainless / Duplex Steel
  • ASTM A182 F 304/304L, 316/316L, 321, 347, 348 (stainless steel flanges), 904/904L
  • ASTM A182 F51 (duplex flanges) / F53-F55 (superduplex)