DIN EN ISO 8062-3:2023-05

Clearly define dimensional, geometrical and positional tolerances for castings

DIN EN ISO 8062-3 specifies general dimensional, geometrical and positional tolerances as well as machining allowances for castings. It helps designers, foundries and quality professionals define requirements for cast components consistently and simplify communication between design, manufacturing and inspection. The standard is part of the GPS system (Geometrical Product Specifications) and provides a reliable basis for specifying and evaluating castings.

What is DIN EN ISO 8062-3 about?

The standard defines rules for dimensional, geometrical and positional tolerances for castings and for specifying machining allowances. It focuses on dimensional casting tolerance grades (DCTG), geometrical casting tolerance grades (GCTG), draft angles and required machining allowance grades (RMAG) for different casting processes and materials. It also describes the use of datum systems and how requirements are indicated in technical drawings and product documentation.

New additions include provisions on draft angles, including new definitions for external and internal draft angles, as well as additional requirements for tolerancing and datum systems.

Topics covered

• General dimensional, geometrical and positional tolerances for castings
• Dimensional casting tolerance grades DCTG and geometrical casting tolerance grades GCTG
• Draft angles for different casting processes
• Machining allowances and required machining allowance grades RMAG
• Datum systems and GPS-compliant tolerancing
• Straightness, flatness, roundness, parallelism and perpendicularity tolerances
• Coaxiality and symmetry tolerances
• Information in technical drawings and product documentation
• Requirements for the evaluation of castings

Practical relevance

Castings are used in almost every area of mechanical engineering, plant engineering and vehicle manufacturing. DIN EN ISO 8062-3 helps companies specify tolerances and machining allowances consistently and define castings cost-effectively. This simplifies drawings, reduces coordination effort and ensures that manufacturing requirements are documented transparently.

The provisions on DCTG, GCTG and RMAG grades are particularly relevant, as they form the basis for manufacturing processes, machining effort and quality inspections. At the same time, the standard facilitates the application of modern GPS rules in foundry technology.

Changes compared with DIN EN ISO 8062-3:2008-09

The 2023 edition was extensively revised. The most important changes include:

• Clarification of the scope and title with regard to general dimensional, geometrical and positional tolerances as well as machining allowances
• Introduction of the terms draft angle, external draft angle and internal draft angle
• New clauses and tables on draft angles for different casting processes
• Change from dimensional casting tolerance grade DCTG 16 to DCTG 15wt for wall thicknesses
• Revision of the rules for dimensional, geometrical and positional tolerances
• Clarification of the clause on the rejection of castings
• Correction and expansion of various annexes and application examples

Target audience

• Designers and development engineers
• Foundries and casting manufacturers
• Quality managers
• Manufacturing engineers
• Technical draughtspersons and CAD users
• Inspection and measurement technicians
• Mechanical and plant engineering companies
• Geometrical Product Specifications (GPS) specialists

Conclusion

DIN EN ISO 8062-3 provides the central basis for the tolerancing and specification of castings within the GPS system. With its provisions on dimensional, geometrical and positional tolerances, machining allowances and datum systems, it supports cost-effective manufacturing, unambiguous technical documentation and reliable quality assessment of cast components.

This document replaces DIN EN ISO 8062-3:2008-09 .