BS 6615:1996

Committees responsible
National foreword
Introduction
Specification
1 Scope
2 Normative references
3 Definitions
4 Dimensioning
5 Tolerance grades
6 Mismatch
7 Wall thickness
8 Tapered features
9 Position of tolerance zone
10 Required machining allowances, RMA
11 Indication on drawings
Annexes
A (informative)
B (informative) Required machining allowance grades
     (RMA)
C (informative) Bibliography
Tables
1 Casting tolerances
2 Required machining allowances (RMA)
A.1 Tolerance grades for long-series production raw
     castings
A.2 Tolerance grades for short-series or single-
     production raw castings
Figures
1 Drawing indications
2 Tolerance limits
3 Maximum mismatch
4 Tolerance zone on tapered features
5 External machining of boss
6 Internal machining
7 Machining of step dimension
8 Machining on one side of feature
9 Largest overall dimension of the casting after
     final machining
10 Indication of required machining allowance on
     individual surfaces

Describes a system of tolerance grades and required machining allowance grades for dimensions of castings. Applies to dimensions of cast metals and their alloys which are produced by various casting manufacturing processes. Applicable both to general tolerances and/or required machining allowances given on a drawing and to individual tolerances and/or machining allowances shown immediately following a specific dimension. Applicable when the foundry provides the pattern or die equipment or accepts responsibility for proving it.