This standard specifies those requirements for castings including terms and definitions of dimensional tolerance, geometrical tolerance and machining allowance as well as dimension indication method, dimensional tolerance grade, geometrical tolerance grade, required machining allowance grade and the indications on the drawing.
It is applicable to castings produced by various casting methods.
2 Normative References
The following documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 131 Geometrical Product Specifications (GPS) - Indication of Surface Texture in Technical Product Documentation
GB/T 1182 Geometrical Product Specifications(GPS) - Geometrical Tolerancing - Tolerances of Form, Orientation, Location and Run-out
GB/T 1800.1 Geometrical Product Specifications (GPS) - Limits and Fits - Part 1: Bases of Tolerances, Deviations and Fits
GB/T 1800.2 Geometrical Product Specifications (GPS) - Limits and Fits - Part 2: Tables of Standard Tolerance Grades and Limit Deviations for Holes and Shafts
GB/T 4458.5 Mechanical Drawings - Indication of Tolerances for Size and of Fits
GB/T 5611 Foundry Terminology
GB/T 16892 Geometrical Tolerancing Indication of Non-rigid Parts
GB/T 17851 Geometrical Product Specifications (GPS) - Geometrical Tolerancing - Datums and Datum System
GB/T 24744 Geometrical Product Specifications (GPS) - Drawing Indications for Moulded Parts in Technical Product Documentation (TPD)
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 5611 and the followings apply.
3.1
nominal dimension of casting
design dimension of a rough casting before machining (see Figure 1), including the necessary machining allowance (see Figure 2)
