BS 450:1958

Dimensions, tolerances and general requirements for sizes above and below 3/16 in. Covers screws of the following types: 90 degrees countersunk and raised countersunk, round, pan, cheese and mushroom with slotted and with recessed heads. Appendices on dimensions of hexagon head screws and hexagon precision nuts in sizes below 3/16 inch; flushness gauge for countersunk heads; penetration of standard gauge points for recessed heads; formulae for dimensions; tables of standard sizes.Cross References:BS 57BS 84BS 1473BS 1475BS 1476BS 1580BS 1981BS 2827BS 3643 BS 4183Handbook No. 18