ASTM A307
ASTM A307 Grade A/B Bolts, Stud Bolts, Threaded Rods
ASTM A307 - Standard Specification for Carbon Steel Bolts, Studs, and Threaded Rod 60000 PSI Tensile Strength
This specification covers the chemical and mechanical requirements for three grades (Grades A, B, and C) of carbon steel bolts and studs in specified sizes. However Grade C has been replaced by another specification under ASTM F1554 Grade 36. This specification does not cover the requirements for machine screws, thread cutting/forming screws, mechanical expansion anchors, or other similar externally threaded fasteners. When tested, sampled specimens shall adhere to specified values for chemical composition, hardness, tensile strength, yield point, elongation, and dimensions.
ASTM A307 Grades
| Grade A | Hex Headed Bolts, studs and threaded rods or any other bolting having a minimum tensile strength of 60 ksi, intended for general purpose applications. |
| Grade B | Hex Headed Bolts, studs, and threaded rods or any other bolting having a tensile strength of 60 to 100 ksi and intended for flanged joints in piping systems. |
ASTM A307 Chemical Composition
| Element % | Grade A | Grade B |
|---|---|---|
| Carbon, Max | 0.29 | 0.29 |
| Manganese, Max | 1.2 | 1.20 |
| Phosphorus, Max | 0.04 | 0.04 |
| Sulfur, Max | 0.15 | 0.05 |
ASTM A307 Mechanical Properties
| Grade | Tensile, ksi | Yield, min, ksi | Elongation, min, % |
|---|---|---|---|
| A | 60 min | -- | 18 |
| B | 60-100 | -- | 18 |
Compatible Nuts for ASTM A307 Bolting
| ASTM A307 Grade A | ASTM A307 Grade B | Washers | |
|---|---|---|---|
| 1/4" to 1-1/2" | 1-5/8" to 4" | 1/4" to 4" | |
| ASTM A563 A Hex | ASTM A563A Heavy Hex | ASTM A563A Heavy Hex | ASTM F844 |
ASTM A307 Marking Requirements
| Grade | Details |
|---|---|
| Grade A | Grade A Bolts are marked or stamped with "307A" along with optional manufacturer's Initial or logo. |
| Grade B | Grade B Bolts are marked or stamped with "307B" along with optional manufacturer's Initial or logo. |
