ASTM A 307[ AREAS-963 ]
The ASTM A307 specification covers carbon steel bolts and studs ranging from 1/4″ through 4″ diameter.
The mill bolt specification often manufactured using A36 round bar. There are three grades A, B, and C* which denote tensile strength, configuration, and application. Refer to the Mechanical Properties Chart for the subtle strength differences within each grade.
ASTM A307 Chemical properties
ASTM A307 Mechanical properties
Yield, min, ksi
Elong %, min
60 - 100
58 - 80
ASTM A307 Marking
Bolts are marked or stamped with “307A” along with RFL logo or as per customer need.
Bolts are marked or stamped with “307B” along with RFL logo or as per customer need.
Bolts are marked or stamped with “307C” along with RFL logo or as per customer need.