Note: In 2016, ASTM A325 was officially withdrawn and replaced by ASTM F3125, in which A325 now becomes a grade under the F3125 specification. The F3125 specification is a consolidation and replacement of six ASTM standards, including; A325, A325M, A490, A490M, F1852, and F2280.
Prior to its withdrawal in 2016, the ASTM A325 specification covered high strength heavy hex structural bolts from 1/2″ diameter through 1-1/2″ diameter. These bolts are intended for use in structural connections and therefore have shorter thread lengths than standard hex bolts.
Also refer to Specification A449 for quenched and tempered steel bolts and studs with diameters greater than 1-1/2″ but with similar mechanical properties.