Stainless steel butt weld fittings conform to ASTM A403 material specifications and ASME B16.9 dimensional standards. They are available in sizes from 1/2' to 48' NB, wall thicknesses spanning Schedule 5S to XXS, and popular austenitic grades like SS304, SS304L, SS316, and SS316L. Material and Dimension Standards • Material Specification: ASTM A403 / ASME SA403 (Wrought Austenitic Stainless Steel Piping Fittings) • Dimension Standards: ASME/ANSI B16.9 (Factory-Made Wrought Buttwelding Fittings), ASME B16.28 (Short Radius Elbows and Returns), and MSS-SP-43 (Wrought Stainless Steel Butt-Welding Fittings) • Size Range: 1/2' NB to 48' NB (Nominal Bore) for seamless and welded configurations Grades and Types • Common Stainless Steel Grades: • SS304 / 304L (General corrosion resistance and high weldability) • SS316 / 316L (Higher corrosion/pitting resistance due to molybdenum addition) • Higher Grades: SS321, SS310, SS347, and 904L • Manufacturing Types: Seamless, Welded, or 100% Radiography Tested/Fabricated Schedules and Wall Thickness • Thin/Light Schedules: Sch 5S, Sch 10S • Standard Schedules: Sch 40S, STD, Sch 80S, XS • Heavy Schedules: Sch 160, XXS Common Configurations • Elbows: 45°, 90°, and 180° (Long Radius [LR] and Short Radius [SR]) • Tees: Equal Tee and Reducing Tee • Reducers: Concentric Reducer and Eccentric Reducer • Other Types: Pipe End Caps, Stub Ends (Lap Joint), and Crosses