BS 4933-10-1973
90° Countersunk square bolts
BS 4933-11-1973
120° Countersunk square bolts
BS 325-5-1947
Black 80° countersunk square neck bolts for iron and steel work-Table 5
BS 325-6-1947
Black 110° countersunk square neck bolts for iron and steel work-Table 6
BS 4933-10-2010
90° Countersunk square bolts
BS 4933-10-2015
90° Countersunk square bolts
BS 4933-11-2010
120° Countersunk square bolts
BS 4933-11-2015
120° Countersunk square bolts