ASTM A307
This specification covers the chemical and mechanical requirements of two grades of carbon steel bolts and studs in sizes ½” in. through 4 in. The fasteners are designated by “Grade” denoting tensile strength and intended use, as follows:

A ASTM A307 Grade A Headed bolts, threaded rods and bent bolts intended for general applications.
B ASTM A307 Grade B Heavy hex bolts and studs intended for flanged joints in piping systems with cast iron flanges.
C* ASTM A307 Grade C Anchor bolts, either bent or straight, intended for structural anchorage purposes. The end of a grade C anchor bolt intended to project from the concrete will be painted green for identification purposes. Permanent marking is a supplemental requirement. *As of August 2007, grade C has been replaced by specification F1554 grade 36. We can supply grade C, if required by the project. 

A307 CHEMICAL PROPERTIES

Element Grade A Grade B
Carbon, Max 0.29% 0.29%
Manganese, Max 1.20% 1.20%
Phosphorus, Max 0.04% 0.04%
Sulfur, Max 0.15% 0.05%

A307 MECHANICAL PROPERTIES

Grade Tensile, Ksi Yield, Min, Ksi Elong %, Min
A 60 Min – – 18
B 60 – 100 – – 18
C* 58 – 80 36 23

A307 RECOMMENDED ASSEMBLY COMBINATION

Nuts Washers
ASTM A563 Gr. A & B F844/F436
½” – 4″ ½” – 4″