ASTM A307

ASTM A307 covers carbon steel bolts and studs in sizes ranging from 1/4" to 4" in diameter. It is one of the most common, general-purpose bolt specifications, often produced from A36 round bar. The standard includes three grades — A, B, and C* — which differ in tensile strength, configuration, and intended application. For detailed strength variations within each grade, refer to the Mechanical Properties Chart.

A307 Grades

A		Used for general-purpose applications such as headed bolts, bent bolts, and threaded rods where no special strength requirements are specified.
B		Typically supplied as heavy hex bolts or studs, designed for use in flanged joints within piping systems, especially with cast iron flanges.
C*		Primarily intended for straight or bent anchor bolts used in structural anchoring. Bolts projecting from concrete are often painted green for identification. *Note: Since August 2007, Grade C has been replaced by ASTM F1554 Grade 36. However, Grade C may still be supplied upon request.