Enter a nominal size and a hole/shaft designation (e.g. H7 / g6) to get limits, deviations, and fit classification. Covers 3-500mm, IT5-IT9. Nothing leaves your browser.
Yes, completely, no limit. This is a table lookup and arithmetic that runs entirely in your browser, no AI, no backend call at all.
Holes: H, G, F, K, M, N, P, JS. Shafts: h, g, f, k, m, n, p, js. Grades IT5 through IT9, sizes 3mm to 500mm. Letters beyond this set (s, u, r, and similar) aren't included yet because their published deviation values weren't verified against a primary source for every size bracket, shipping an unverified number felt worse than not having it.
Fundamental deviations are hardcoded from published ISO 286-1 tables, not derived from a formula, that's deliberate, since deviation values are tabulated data, not something you can safely approximate. IT grade widths are computed from the standard tolerance unit formula and cross-checked against the published grade tables.
This is a quick design aid, not a substitute for checking the actual ISO 286-1/286-2 standard on a critical dimension. Sizes outside 3-500mm use different rules and aren't covered.