BS 1981:1991
Specification for unified machine screws and machine screw nuts

Standard No.

BS 1981:1991

Release Date

1991

Published By

British Standards Institution (BSI)

Latest

BS 1981:1991

Replace

89/79991 DC-1990 BS 1981:1972

Scope

Applicable to machine screws and machine screw nuts having ISO inch screw threads and hexagon head and slotted or recessed heads with type Z and type V recess. Mechanical properties are specified for steel, brass and aluminium alloy screws and nuts.

BS 1981:1991 history

• 1991 BS 1981:1991 Specification for unified machine screws and machine screw nuts