Until recently, A325s have been limited as to what their configuration can be. The head style has always been a heavy hex and they are used for steel to steel connections only. The steel to steel connection application requirement has not changed, however with the implementation of ASTM F3125, A325s have more options in regards to the configuration. Per supplemental requirement “S2”, they can now have different head styles and longer than standard thread lengths, as long as the head is stamped “A325S”.

Since the standard configuration of an A325 structural bolt can be altered under the F3125 supplemental requirement, does this mean that A325 lag screws will be available or manufactured on a custom order basis? The answer is no. The reason is they are still a structural bolt used in steel to steel connections, which would not apply to lag screws. Lag screws available in the marketplace are low carbon steel, however they can be made in higher strength grades. If the strength of an A325 is desired, then ASTM recommends A449 for fasteners used in applications other than structural steel connections.