TS EN ISO 8062-3

TS EN ISO 8062-3 is a part of the GPS framework dealing with general dimensional and geometrical tolerances, together with machining allowance grades, for castings. It provides a common reference for castings delivered to the purchaser in accordance with ISO 8062-2, so the document is about the default tolerance basis used for cast parts rather than item-by-item bespoke tolerance specification.

What dimensional tolerance and machining allowance mean in casting

In casting, dimensional variation is inherent to the process because mould behaviour, solidification, shrinkage and material response all influence the final shape. Geometrical tolerances describe how much a surface or feature may deviate in form, orientation, location or run-out. Machining allowance is the extra stock intentionally left on a casting so that subsequent machining can bring the part to final size and surface condition. In practical terms, this standard supports a shared technical language between design, foundry production and machining.

What this part covers

• General dimensional tolerances for castings delivered in accordance with ISO 8062-2
• General geometrical tolerances for castings
• Machining allowance grades

Within the broader GPS system, such tolerance grades help balance manufacturability against functional requirements. The standard addresses the general deviation basis to be considered for castings before final use, while the actual class selected in practice depends on the part function, casting process and the amount of follow-up machining needed. As a result, it is especially relevant in technical drawings and product definition for cast components.

This TS EN ISO 8062-3 edition has been withdrawn, but it remains a useful technical reference for understanding casting tolerances, geometrical product specifications and machining allowance concepts.