ASTM A234 / A234M

This specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction covered by the latest revision of ASME B16.9, B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, and MSS-SP-97. These fittings are for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. Fittings differing from these ASME and MSS standards shall be furnished in accordance with Supplementary Requirement S58 of Specification A960/A960M.

Chemical Properties

Grade	Carbon	Manganese	Phosphorus	Sulfur	Silicon	Chromium	Molybdenum	Nickel	Copper	Others

Note B: Fittings made from bar or plate may have 0.35 max carbon.

Note C: Fittings made from forgings may have 0.35 max carbon and 0.35 max silicon with no minimum.

Note D: For each reduction of 0.01 % below the specified carbon maximum, an increase of 0.06 % manganese above the specified maximum will be permitted, up to a maximum of 1.65 %.

Note E: The sum of Copper, Nickel, Chromium, and Molybdenum shall not exceed 1.00 %.

Note F: Applies both to heat and product analyses.

Mechanical Properties

Grade	Tensile strength, min ksi [MPa]	Yield strength, min, ksi [MPa] (0.2 % offset)

Note A: WPB and WPC fittings manufactured from plate shall have a minimum elongation of 17 %.

Note B: Fittings made from bar or plate may have 0.35 max carbon.

Note C: Fittings made from forgings may have 0.35 max carbon and 0.35 max silicon with no minimum.

Note D: For each reduction of 0.01 % below the specified carbon maximum, an increase of 0.06 % manganese above the specified maximum will be permitted, up to a maximum of 1.65 %.

Note E: The sum of Copper, Nickel, Chromium, and Molybdenum shall not exceed 1.00 %.

Note F: Applies both to heat and product analyses.

Grade	Elongation
	Standard round specimen, min % in 4 D		Rectangular specimen for wall thickness 5/₁₆		Rectangular specimen for wall thickness less than 5/₁₆
	Longitudinal	Transverse	Longitudinal	Transverse	Longitudinal	Transverse

Note A: WPB and WPC fittings manufactured from plate shall have a minimum elongation of 17 %.

Note B: For each 1/₃₂ in. [0.79 mm] decrease in wall thickness below 5/₁₆ in. [7.94 mm], a deduction of 1.5 % for longitudinal and 1.0 % for transverse from the values shown above is permitted. The following table gives the minimum value for various wall thicknesses.

Note C: Fittings made from forgings may have 0.35 max carbon and 0.35 max silicon with no minimum.

Note D: For each reduction of 0.01 % below the specified carbon maximum, an increase of 0.06 % manganese above the specified maximum will be permitted, up to a maximum of 1.65 %.

Note E: The sum of Copper, Nickel, Chromium, and Molybdenum shall not exceed 1.00 %.

Note F: Applies both to heat and product analyses.