What is BS EN ISO 8062-3 - Geometrical tolerances and machining allowances for castings about?
This is the third standard in ISO’s Geometrical Product Specifications (GPS) series on dimensional and geometrical tolerances for moulded parts, which help designers and manufacturers specify castings that achieve more accurate products. BS EN ISO 8062-3:2023 defines a system of tolerance grades and machining allowance grades for cast metals and their alloys.
Who is BS EN ISO 8062-3 - Geometrical tolerances and machining allowances for castings for?
- Mechanical engineers, design engineers, engineering designers, manufacturing engineers and production engineers who work in the aerospace, defence, automotive, rail, nuclear, and medical devices sectors
- Engineering or manufacturing organizations who produce castings as part of their manufacturing and development processes
What does BS EN ISO 8062-3 - Geometrical tolerances and machining allowances for castings cover?
It specifies general dimensional and geometrical tolerances as well as machining allowance grades for castings using ± tolerances for indicated dimensions as delivered to the purchaser according to PD CEN ISO/TS 8062-2. It applies to tolerancing of dimensions and geometry of castings in all cast metals and their alloys produced by various casting manufacturing processes.
BS EN ISO 8062-3 applies to both general dimensional and general geometrical tolerances (referred to in or near the title block of the drawing), unless otherwise specified and where specifically referred to on the drawing.
The dimensional tolerances covered by BS EN ISO 8062-3 are tolerances for linear dimensions. The geometrical tolerances are tolerances for:
- straightness
- flatness
- roundness
- parallelism
- perpendicularity
- symmetry
- coaxiality
BS EN ISO 8062-3:2023 can be used for the selection of tolerance values for individual indications.
NOTE: BS EN ISO 8062-3:2023 does not apply to 3D CAD models used without indicated dimensions, nor does it cover other position tolerances, angular dimensional tolerances or cylindricity tolerances.
Why should you use BS EN ISO 8062-3 - Geometrical tolerances and machining allowances for castings?
- It provides a consistent approach for tolerancing and allowances for castings
- It enables users to achieve more accurate products
- It can help users enter new markets and increase confidence in products
- BS EN ISO 8062-3 is an updated and improved version that’s clearer and more user-friendly than its predecessor
What’s new about BS EN ISO 8062-3:2023?
This is a revision of BS EN ISO 8062-3:2007, which has been updated and corrected for clarity. The major changes in BS EN ISO 8062-3:2023 are:
- A revised title and scope, clarifying that this document specifies general dimensional and geometrical tolerances as well as machining allowance grades for castings using ± tolerances for indicated dimensions
- Additional definitions for the terms “draft angle”, “external draft value” and “internal draft angle”
- Additional clauses and tables, and renumbering of subsequent clauses and tables
- The linear dimensional casting tolerance grade DCTG 16 is changed to DCTG 15wt to clarify the concept of wall thickness
- The nominal dimension to be used in the tables indicating casting tolerances for straightness, flatness, roundness, parallelism, perpendicularity, symmetry and coaxiality is changed
- Clause 12 on rejection is clarified
- The correction according to ISO 8062-3:2007/Cor 1:2009 is added in Table A.3, footnote b
- The examples given in Annex E are corrected
- Inconsistencies are clarified
