Unlike high-strength bolts, ASTM A307 fasteners are not quenched and tempered. Quenching involves rapid cooling to harden steel, which makes it brittle, followed by tempering to restore toughness. A307 bolts skip this process entirely, remaining in a "hot-rolled" or normalized state. This absence of heat treatment is why they maintain lower strength but higher ductility.

: Assembly of machinery where high-strength (e.g., Grade 5 or 8) bolts are not required.

: General purpose bolts and studs with a minimum tensile strength of 60,000 psi (414 MPa) . These are common in structural steel and cast iron connections.

ASTM A307 remains the workhorse of low-strength, general-purpose fasteners. When specifying A307, always include the grade (A or B) and the finish (plain, zinc-plated, or galvanized). For any application requiring controlled yield strength or weldability, consider upgrading to ASTM F1554 Grade 36.

The ASTM A307 standard is divided into three distinct grades, each tailored for specific applications and mechanical environments.