Class | Heat Treatment |
Thickness | Yield Strength, min, ksi [MPa] |
Tensile Strength, min, ksi [MPa] |
A537 Class 1 | Normalized | 21/2 in. and under [65 mm and under] | 50 [345] |
70 [485] |
Over 21/2 in. [Over 65 mm] |
45 [310] |
65 [450] |
||
A537 Class 2 | Quenched and tempered | 21/2 in. and under [65 mm and under] | 60 [415] |
80 [550] |
Over 21/2 to 4 in. [Over 65 to 100 mm] |
55 [380] |
75 [515] |
||
Over 4 in. [Over 100 mm] |
46 [315] |
70 [485] |
||
A537 Class 3 | Quenched and tempered | 21/2 in. and under [65 mm and under] | 55 [380] |
80 [550] |
Over 21/2 to 4 in. [Over 65 to 100 mm] |
50 [345] |
75 [515] |
||
Over 4 in. [Over 100 mm] |
40 [275] |
70 [485] |
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