1/4″ UNF Hex Nyloc

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

A 1/4 BSF hexagon set bolt (threaded up to head)Under head dimension: 3/8". Standard hexagon size (.445" A/F)Head machined flat (no markings).

A 5/16 BSF hexagon set bolt (threaded up to head)Under head dimension: 1-1/4". 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: 3/4". Standard hexagon size (.525" A/F)Head machined flat (no markings).