High Strength Bolts

High strength bolts are used in heavy structure joint. Its mostly produced by middle carbon steel C1035, C1045 steel and alloy steels (4140, 40Cr, 42CrMo4), quenched and tempered.

Due to it's heavy structure joint purpose, the normal available specifications of the bolts size is 1/2" or M12 up to 1.1/2" or M42. The related dimensional standard as per ANSI/ASME B18.2.6 and for material & testing standards as follows,

ASTM A325-09a Standard Specification for Structural Bolts, Steel, Heat
Treated, 120/105 ksi Minimum Tensile Strength

ASTM A490-09 Standard Specification for Heat-Treated Steel Structural
Bolts, 150 ksi Minimum Tensile Strength

High Strength Bolts usually have a protection coating by hot dipper galvanizing or dacromated.