Grade A
A307 Grade A is the most generic and readily available fastener in the marketplace for general applications. It does not have any configuration limitations, meaning it can be made as a headed bolt, bent bolt, or straight threaded rod.
Mechanical Properties
| Nominal Size | Mechanical Properties | Hardness Rockwell | |||||
|---|---|---|---|---|---|---|---|
| Proof Load | Yield Str. | Tensile Str. | Elong. % | R.A. % | Min | Max | |
| 1⁄4” – 4″ | – | – | 60 ksi min | 18 min | – | B69 | B100 |
Grade B
A307 Grade B has configuration limitations in the fact that it can only be manufactured as a heavy hex bolt or fully threaded stud. These parts are intended to be used for flanged joints in piping systems, specifically with cast iron flanges. Unlike most ASTM fastener specifications, A307 Grade B bolts have not only a minimum tensile strength requirement (60 ksi), but also have a maximum tensile strength requirement of 100ksi.
Mechanical Properties
| Nominal Size | Mechanical Properties | Hardness Rockwell | |||||
|---|---|---|---|---|---|---|---|
| Proof Load | Yield Str. | Tensile Str. | Elong. % | R.A. % | Min | Max | |
| 1⁄4” – 4″ | – | – | 60 min 100 max | 18 | – | B69 | B95 |
Grade C
A307 Grade C applied to non-headed anchor bolts in either bent or straight forms before it was withdrawn from the specification. It had a special marking requirement for the projecting end to be painted green for easy identification. A permanent marking was a supplemental requirement and needed to be specified. This specification was replaced in August 2007, by the F1554 Grade 36 specification. This specification comes up occasionally when old plans and specifications are used for the procurement of anchor bolts, and Portland Bolt continues to supply Grade C if required by the project.
Mechanical Properties
| Grade | Tensile, ksi | Yield, min, ksi | Elong %, min |
|---|---|---|---|
| C* | 58 – 80 | 36 | 23 |