IS 3469: Indian Forging Tolerance Standard
IS 3469 is the Indian standard that sets dimensional tolerances for drop and press forgings in steel. If your drawing simply says “as per IS 3469” without naming a grade, you have not actually specified a tolerance — and that ambiguity is where most Indian forging disputes begin.
IS 3469 is the Indian standard defining dimensional tolerances for steel drop and press forgings. It sets permissible variation for length, thickness, die mismatch, flash extension, straightness and draft, graded by forging weight, with a fine grade and a commercial grade.
- Standard
- IS 3469 (Parts 1–3)
- Applies To
- Steel drop and press forgings
- Grades
- Fine (F) and commercial (E)
- Controls
- Dimensions, mismatch, flash, draft
- Scales With
- Forging weight and size
- Equivalent To
- DIN 7526, ISO 8062 family
Key takeaways
- Citing “IS 3469” without a grade does not specify a tolerance — always name fine or commercial grade.
- Allowed variation scales with forging weight, so a 40 kg part legitimately holds looser limits than a 2 kg one.
- Fine grade genuinely costs more; apply it only to dimensions that carry a function.
- Tight tolerances belong on machined features, never on as-forged surfaces.
IS 3469: Indian Forging Tolerance Standard at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Standard: IS 3469 (Parts 1–3)
- Applies To: Steel drop and press forgings
- Grades: Fine (F) and commercial (E)
- Controls: Dimensions, mismatch, flash, draft
- Scales With: Forging weight and size
- Equivalent To: DIN 7526, ISO 8062 family
What the Standard Covers
IS 3469 defines permissible variation for length, width, thickness, mismatch, flash extension, straightness and draft on steel forgings, scaled by the forging's weight and size. Larger forgings are allowed proportionally more variation, because thermal shrinkage and die wear scale with size.
- Length, width and thickness limits
- Die mismatch and flash extension
- Straightness and flatness
- Tolerances scale with forging weight
Grades and What They Cost
The standard splits tolerances into grades — commonly cited as F (fine) and E (commercial or ordinary). Fine grade demands tighter die control, more frequent die maintenance and closer weight control, so it legitimately costs more. Specify fine grade only on dimensions that matter functionally.
How to Specify It Properly
Name the grade, and apply tighter tolerances only to machined features rather than to as-forged surfaces. A drawing that puts ±0.1 mm on an as-forged dimension cannot be met by any forge, and reviewing that before tooling is cut saves an expensive argument later.
Topics covered on this page
- IS 3469 forging tolerance
- IS 3469 standard explained
- Indian forging tolerance standard
- IS 3469 grade F
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is IS 3469?
+
The Indian standard specifying dimensional tolerances for steel drop and press forgings, covering length, thickness, mismatch, flash extension, straightness and draft.
What is the difference between grade E and grade F?
+
Fine grade (F) permits less variation and costs more to hold; commercial grade (E) is the economical default. Use fine grade only where function demands it.
Is IS 3469 the same as DIN 7526?
+
They are close counterparts covering the same dimensional characteristics with comparable grade structures, though the exact numeric limits differ.
Do you work to IS 3469?
+
Yes. Our closed die work is normally quoted to IS 3469 or DIN 7526 class E–F unless a customer specifies otherwise.