BS 57:1951

Co-operating organizations
Foreword
Specification
Section one: Screws, bolts and nuts
1 Scope
2 Method of manufacture
3 Material
4 Dimensions
5 Length of screws and bolts
6 Ends of screws and bolts
7 Screw threads
8 Length of thread on screws and bolts
9 Chamfering and washer-facing
Tables
1 Cheese head screws
2 Round head screws
3 Countersunk head screws
4 Raised-countersunk (instrument) head screws
5 Hexagonal headed screws and bolts
6 Hexagonal ordinary (or full) and thin (or lock) nuts
7 Lengths of steel and brass cheese and countersunk
    head B.A. screws (screwed to head)
8 Lengths of steel and brass round head B.A. screws
    (screwed to head)
9 Lengths of steel and brass raised-countersunk
    (instrument) head B.A. screws (screwed to head)
10 Lengths of steel hexagonal head B.A. screws (screwed
    to head) and bolts (2 B.A. only)
Appendices
Appendix A: Special types of screw not normally stocked:
    Table 13. Raised cheese (fillister) head screws
    Table 14. Connection head screws
Appendix B: Approximate proportions
Appendix C: Metric slot widths:
    Table 15. Slot widths

Heads: cheese, round, countersunk, raised-countersunk, hexagonal; hexagonal nuts, ordinary and locknut; range No. 0 to No. 16 B.A. Standard lengths of screws.

Section 1 of this British Standard specifies requirements and dimensions for both ferrous and non-ferrous screws, bolts and nuts.