ISO 8062 & Dimensional Tolerance Systems
ISO 8062 provides a systematic tolerance grade framework for dimensionally formed parts. Buyers who work across castings and forgings meet it regularly, and its logic — grade plus size determines the limit — underpins how every forging tolerance standard is structured.
ISO 8062 is a systematic framework of dimensional tolerance and machining allowance grades for dimensionally formed parts. A tolerance grade combined with the nominal dimension determines the permissible variation, the same logic underlying forging standards IS 3469 and DIN 7526.
- Standard
- ISO 8062 series
- Principle
- Tolerance grade plus nominal size
- Also Covers
- Required machining allowance grades
- Primary Use
- Castings and formed parts
- Forging Practice
- IS 3469, DIN 7526 more commonly cited
- Benefit
- Systematic cross-process comparison
ISO 8062 & Dimensional Tolerance Systems at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Standard: ISO 8062 series
- Principle: Tolerance grade plus nominal size
- Also Covers: Required machining allowance grades
- Primary Use: Castings and formed parts
- Forging Practice: IS 3469, DIN 7526 more commonly cited
- Benefit: Systematic cross-process comparison
The Grade and Size Principle
A tolerance grade is chosen, then the permissible variation is read against the nominal dimension. Larger dimensions carry proportionally larger tolerance, because thermal and process variation scale with size rather than staying constant.
- Grade plus nominal size gives the limit
- Larger dimensions, larger tolerance
- Systematic rather than ad hoc
- Shared logic with IS 3469 and DIN 7526
Required Machining Allowance
The framework also addresses machining allowance grades — the stock deliberately left for machining. Specifying allowance systematically prevents both the undersize part that cannot clean up and the oversize one that wastes machining time.
Applying It to Forgings
Forging buyers normally cite IS 3469 or DIN 7526 in practice, but understanding the ISO framework helps when a drawing mixes conventions or when comparing quotes from suppliers working to different standards.
Topics covered on this page
- ISO 8062 tolerance
- dimensional tolerance grades formed parts
- casting tolerance standard
- ISO 8062 explained
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is ISO 8062?
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An ISO framework of dimensional tolerance and machining allowance grades for dimensionally formed parts such as castings, with logic shared by forging tolerance standards.
Does it apply to forgings?
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Its principles do, though forging drawings more commonly cite IS 3469 or DIN 7526.
What is a machining allowance grade?
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A systematic way of specifying how much stock is left for machining, preventing both undersize and wastefully oversize parts.
Which standard should my drawing cite?
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For steel forgings, IS 3469 or DIN 7526 with a named class. We will confirm what we can hold before tooling is cut.