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.
ASTM A307 Grades
| Grade | Identification Marking | Description |
|---|---|---|
| A |  |
Headed bolts, threaded rods and bent bolts intended for 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*As of August 2007, grade C has been replaced by specification F1554 grade 36.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.
ASTM A307 Mechanical Properties
| Grade | Tensile, ksi | Yield, min, ksi | Elong %, min |
|---|---|---|---|
| A | 60 min | -- | 18 |
| B | 60 - 100 | -- | 18 |
| C* | 58 - 80 | 36 | 23 |
ASTM A307 Chemical Properties
| Grade | Tensile, ksi | Yield, min, ksi | Elong %, min |
|---|---|---|---|
| A | 60 min | -- | 18 |
| B | 60 - 100 | -- | 18 |
| C* | 58 - 80 | 36 | 23 |
ASTM A307 Recommended Hardware
| Nuts | Washers | ||
|---|---|---|---|
| A307 Grades A & C* | A307 Grade B | F844 | |
| 1/4 - 1-1/2 | 1-5/8 - 4 | 1/4 - 4 | |
| A563A Hex | A563A Heavy Hex | A563A Heavy Hex | |