Describes requirements and gives general dimensions and tolerances for the following types of cup head and countersunk head bolts and screws: - cup head bolts and screws; - cup head bolts with nibs; - cup head square neck bolts; - 90 degree countersunk head bolts and screws; - 90 degree countersunk head bolts with nibs; - 90 degree countersunk head square neck bolts; and - 120 degree countersunk head square neck bolts.

This British Standard specifies requirements and provides general dimensions and tolerances for the following types of cup head and countersunk head bolts and screws:

• cup head bolts and screws;

• cup head bolts with nibs;

• cup head square neck bolts;

• 90° countersunk head bolts and screws;

• 90° countersunk head bolts with nibs;

• 90° countersunk head square neck bolts;

• 120° countersunk head square neck bolts.

Mechanical properties for steel bolts and screws are specified in BSENISO898‑1.

This British Standard also specifies requirements for the nuts to be provided with bolts and screws conforming to this standard.

NOTE1 A table summarizing the key requirements of BS4933 is included in AnnexA. This table does not list every requirement in BS4933 but is just intended as a quick reference for users.

NOTE2 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, further information is provided in AnnexB.