Kaimera Industries
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KM-T-06 / Machining · Fits & Tolerances

Fits & Tolerance Reference

Hole · shaft · resulting fit. Metric limits from ISO 286-2, sizes over 3 mm up to 400 mm, with preferred hole-basis fits and machining aim points.

Live

A free ISO 286 fits and tolerance calculator. Enter a nominal size and pick a hole and shaft tolerance class to get upper and lower limits for each, the resulting fit type — clearance, transition, or interference — and the min/max gap or press. It also gives an aim point inside each tolerance so you know where to land the cut rather than just where the limits are.

Fits & Tolerance Reference

ISO 286 · Hole / Shaft Limits · Clearance & Interference
Metric · >3–400 mm · inch ANSI B4.1: next pass

Fit selection

plain bearings, accurate sliding location
mm
Not in the verified set yet (ask to add): s6 / u6 heavy shrink fits, c11 / d9 loose running fits, and the inch ANSI B4.1 RC/LC/LN/FN classes — each needs its own verified data pass rather than a guess.

Aim points

Where inside each tolerance band do you want your actual parts to land? Drag each, read the machining target, and see the fit those two targets would actually produce.
Hole target (H7)25.011 mm
25.00025.021
Shaft target (g6)24.986 mm
24.98024.993
Fit at these two targets
+24.0µm
clearance (hole larger)
25 mm H7/g6 — resulting fit
+7.0to+41.0µm
CLEARANCE FIT · positive = clearance, negative = interference
Hole H7 limits
25.000 – 25.021mm
deviations +0 / +21 µm
Shaft g6 limits
24.980 – 24.993mm
deviations -20 / -7 µm
Reading it: any hole made inside 25.000–25.021 paired with any shaft inside 24.980–24.993 lands somewhere in the fit band above. The aim-point sliders answer the follow-up question: where should you machine each part to land where you want inside that band.
Sources & verification: deviation values per ISO 286-2 published tables (sizes >3–400 mm), cross-checked against independently published worked examples (H7/g6 at 20 mm, H7/p6 at 28 mm, g6 and IT grades at 30–50 mm) and against the ISO 286-1 derivation formulas for every cell. Fit clearance/interference is computed as hole minus shaft at the limit extremes; values assume 20 °C and ideal geometry — form error, surface finish, and temperature all eat into real clearance on tight fits.

Scope, honestly: this covers the hole-basis classes that do the daily work — H6–H11 (plus G7/F8) against e/f/g/h/js/k/m/n/p/r shafts. Heavy shrink fits (s6, u6), loose running fits (c11, d9), sub-3 mm, over-400 mm, and the inch ANSI B4.1 system are deliberately absent until they get their own verified pass. Always confirm against the standard or Machinery's Handbook for safety-critical fits.

§ Common Questions

Frequently asked

What does H7/h6 mean?
H7 is a hole tolerance class and h6 a shaft class in the ISO 286 system. Together they form a close sliding fit: the hole never goes below nominal, the shaft never goes above, so the parts always assemble with a small clearance.
Which fit do I use for a press fit?
Interference classes such as H7/p6 or H7/s6 are typical press fits. The heavier the class, the more interference and the more force or thermal assembly required.
What is a transition fit?
A transition fit is a class combination where the parts may end up with a small clearance or a small interference depending on where each part lands inside its tolerance. It is used when location matters more than assembly force.

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