In August of 2007, A307 Grade C was officially replaced by the new F1554 Grade 36. Although these two grades are nearly identical, there are some subtle and important differences. These specifications cover anchor bolts to be embedded into concrete. Unlike the A307 Grade C specification, F1554 also allows for headed anchor bolts, whereas A307 Grade C only covered unheaded anchor bolts that were bent or straight. It is preferable to use F1554 Grade 36 instead of A307 Grade C for anchoring purposes. However, Portland Bolt can still manufacture A307 Grade C anchor bolts if a project requires them.

ASTM A307 is a fastener specification whereas A36 is a raw steel specification often used to make A307 bolts. It is always preferable when specifying a fastener to use a fastener specification like A307. This provides the manufacturer with information regarding manufacturing processes, hardware compatibility, thread pitch, and more.

A307 fasteners are often manufactured from A36 steel which is weldable. However, A307 can be manufactured from other raw materials so it is not technically always weldable. If your project requires weldability, you must specify supplemental requirement S1 which outlines the requirements for weldability.