ASTM Grain Size Calculator
Grain diameter and grains-per-area from the ASTM grain size number.
Each ASTM number halves grain area (÷√2 diameter). G8 ≈ 22 µm grains. Finer grain = stronger AND tougher — the only free lunch in metallurgy (Hall-Petch, next tool).
Formula
ASTM Grain Size Calculator is a free astm grain size for design engineers, metallurgists and QA inspectors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About ASTM Grain Size Calculator
Grain diameter and grains-per-area from the ASTM grain size number. The calculation implements n(/in² @100×) = 2^(G−1); d ≈ 1/√(n per mm²) (ASTM E112). Each ASTM number halves grain area (÷√2 diameter). G8 ≈ 22 µm grains. Finer grain = stronger AND tougher — the only free lunch in metallurgy (Hall-Petch, next tool).
How to use ASTM Grain Size Calculator
- 1Enter ASTM grain size number G (Coarse 1–4 · fine 7–10 · ultrafine 12+).
- 2Read Mean grain diameter, Grains per mm² (at 1×) instantly — no submit button needed.
Why use ASTM Grain Size Calculator?
- ✓Implements the standard formula — n(/in² @100×) = 2^(G−1); d ≈ 1/√(n per mm²)
- ✓Reference cited on-page: ASTM E112
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the ASTM Grain Size Calculator use?+
It computes n(/in² @100×) = 2^(G−1); d ≈ 1/√(n per mm²), per ASTM E112. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Each ASTM number halves grain area (÷√2 diameter). G8 ≈ 22 µm grains. Finer grain = stronger AND tougher — the only free lunch in metallurgy (Hall-Petch, next tool).
Where do the material property defaults come from?+
Defaults are standard handbook values (ASM, manufacturer datasheets, the cited standard). Always substitute certified values from your material's test certificate for critical work.
Is the ASTM Grain Size Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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