BS 1937:1953

This British Standard specifies requirements for engineers’ ratchet braces and drilling pillars.

The ratchet braces are of the following types:—

1. Long head (box) type, having an open or totally enclosed ratchet and available with either
   1. Square taper nozzle, or
   2. Morse taper nozzle.
2. Short head type, having an open or totally enclosed ratchet. Suitable for square taper shank drills only.
3. Extra short head type (pin brace), having an open or totally enclosed ratchet. Suitable for square taper shank drills only.
4. Short head type heavy duty (boiler brace), having totally enclosed ratchet, available with square taper nozzle.
5. Bit stock type, having an open or totally enclosed ratchet. Suitable for bit stock drills only.

Nomenclature and definitions are given, together with requirements for materials, heat treatment, hardness, finish and accuracy of assembly. Ranges of dimensions of the various types of brace and of the drilling pillars are also included.

Sizes, dimensions, material, for following open and enclosed drive ratchet braces: long head (box), short head, extra short head (pin brace), short head heavy duty (boiler brace), bit stock. Dimensions of drilling pillars for use with braces. For use with drills having Morse taper or square taper shanks, when necessary employing an adaptor, conversion details of which are included.