ASTM A234 WP12

ASTM A234 Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service


Grade: WP12


Chemical Requirements Composition, %

GradeWP12 CL1


Tensile Requirements

GradeWP12 CL1WP12 CL2
Tensile strength, MPa415–585485-655
Yield strength, min MPa220275


Elongation Requirements

Elongation:WP12 CL1, CL2
Standard round specimen, or small proportional specimen, min % in 4 D2214
Rectangular specimen for wall thickness 5⁄16 in. [7.94 mm] and over,and for all small sizes tested in full section; min % in 2 in. [50 mm]3020 A
Rectangular specimen for wall thickness less than 5⁄16 in. [7.94 mm];min % in 2 in. [50 mm] (1⁄2-in. [12.7-mm] wide specimen)BB

A Fittings manufactured from plate shall have a minimum elongation of 17 %.

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.


Wall ThicknessWP12 CL1, CL2
5⁄16 (0.312)7.943020
9⁄32 (0.281)7.1428.519
1⁄4 (0.250)6.352718
7⁄32 (0.219)5.5625.5
3⁄16 (0.188)4.7624
5⁄32 (0.156)3.9722.5
1⁄8 (0.125)3.1721
3⁄32 (0.094)2.3819.5
1⁄16 (0.062)1.5918

This table gives the computed minimum % elongation value for each 1⁄32 in. [0.79 mm] decrease in wall thickness. Where the wall thickness lies between two values above, the minimum elongation value is determined by the following equations:

Direction of TestEquation
LongitudinalE= 48t + 15.00
TransverseE= 32t + 10.00


E = elongation in 2 in. or [50 mm], %, and

t = actual thickness of specimen, in. [mm].


Hardness: ≤197 HB