3/8″ UNF x 6″ Hex

A 1/4 BSF hexagon bolt (part threaded)Under head dimension: 1-3/4". Thread length: 9/16". Standard hexagon size (.445" A/F)Head machined flat (no markings).

A 5/16 BSF hexagon bolt (part threaded)Under head dimension: 1-1/2".Thread length: 5/8" Standard hexagon size (.525" A/F)Head machined flat (no markings).

A 5/16 BSF hexagon set bolt (threaded up to head)Under head dimension: 2". Standard hexagon size (.525" A/F)Head machined flat (no markings).