Scope
The ASTM A307 specification covers carbon steel bolts and studs ranging from 1/4″ through 4″ diameter. This is your everyday, run of 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.
A307 Grades
A 
Headed bolts, threaded rods and bent bolts intended general applications.
B 
Heavy hex bolts and studs intended for flanged joints in piping systems with cast iron flanges.
C* 
Nonheaded 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 *As of August 2007, grade C has been replaced by specification F1554 grade 36.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 will continue to supply grade C, if required by the project.
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 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 Recommended Hardware
Nuts | Washers | ||
A307 Grades A & C* | A307 Grade B | ||
1/4 – 1-1/2 | 1-5/8 – 4 | 1/4 – 4 | |
A563A Hex | A563A Heavy Hex | A563A Heavy Hex | F844 |