BS 1434:1985

Foreword
Committees responsible
Specification
1. Scope
2. Definitions
3. Information to be supplied by the purchaser
4. General
5. Material
6. Tolerances on dimensions and shape
7. Sampling
8. Determination of hardness
Appendix
A. Preferred nominal sizes
Tables
1. Chemical compositions and minimum hardness
2. Permitted proportions of bars of different actual
     lengths in any one delivery of mill lengths
3. Tolerances on length for specified lengths
4. Tolerances on length for blanks and segments
5. Tolerances on height
6. Thickness measurement positions for commutator
     bar segments or blanks
7. Tolerances on thickness
8. Tolerances on specified angle
9. Tolerances on shape error and shape constants
     for the shape of the side faces
10. Maximum deviation from straightness of bar
11. Maximum twist for bars, blanks and segments
12. Preferred heights, H, in mm, of sections for
     commutator bars
13. Preferred nominal diameters, in mm, of finished
     commutators
Figures
1. Segments
2. Main dimensions of cross sections of commutator
     bar segments or blanks and measuring positions for
     thickness, angle and shape
3. Deviation from specified angle
4. Tolerance on shape of the convex thick edge
5. Tolerance band for the shape of the thin edge
6. Measuring area for Vickers hardness (referee method)

Specifies requirements for flat sided wedge shaped section in bars (straight lengths and coils) blanks and segments, suitable for the manufacture of commutators for rotating machines.

This British Standard specifies requirements for flat sided wedge-shaped copper sections in bars (straight lengths and coils), blanks and segments, suitable for the manufacture of commutators for rotating machines, in the following size ranges:

1. thick edge thickness (T) up to 15 mm;
2. height (H) from 6 mm to 200 mm;
3. height to thin edge ratio (H/t) up to 50.

This standard does not cover copper for flat face commutators, commonly rectangular section strip and bar, which is covered by BS 1432 and BS 1433.

NOTE. The titles of the publications referred to in this standard are listed on the inside back cover.