BS 1768:1963

Specification for Unified precision hexagon bolts, screws, & nuts (UNC & UNF threads). Normal series. | Status: Confirmed, Current

1 Scope This British Standard covers the Normal series of Unified precision hexagon bolts, screws and nuts having Unified screw threads in a range of nominal sizes from ¼ in to 2 in inclusive. The dimensional requirements of this standard apply both to ferrous and non-ferrous bolts, screws and nuts. Mechanical properties are given only in respect of steel bolts, screws and nuts, and the finishes in which they are normally supplied are described in Clause 3.

NOTE It is considered that the range of nominal sizes included in this standard is adequate for most of the applications for which this series is likely to be employed, but for the convenience of users requiring larger sizes, the formulae from which the proportions for bolt heads and nuts are derived are given in Appendix F.