BSI - BS 57
Specification for B.A. Screws bolts and nuts
|Publication Date:||31 March 1951|
|ICS Code (Bolts, screws, studs):||21.060.10|
|ICS Code (Nuts):||21.060.20|
Heads: cheese, round, countersunk, raised-countersunk, hexagonal; hexagonal nuts, ordinary and locknut; range No. 0 to No. 16 B.A. Standard lengths of screws.