Tolerance chart
k5 tolerance (shaft): ISO 286 chart up to 500 mm
k5 is an ISO tolerance class for shafts (external features) under ISO 286. At Ø25 mm it means +11 / +2 µm: the size may lie between 25.002 and 25.011 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use k5.
k5 chart: deviations for all nominal sizes up to 500 mm
Deviations in µm (1 µm = 0.001 mm). A nominal size belongs to the row »over … up to and including …«: exactly 30 mm is in the row ending at 30, 30.1 mm in the next one.
| Nominal size over – to (mm) | Upper deviation | Lower deviation | Tolerance |
|---|---|---|---|
| 0 – 3 | +4 | 0 | 4 |
| 3 – 6 | +6 | +1 | 5 |
| 6 – 10 | +7 | +1 | 6 |
| 10 – 18 | +9 | +1 | 8 |
| 18 – 30 | +11 | +2 | 9 |
| 30 – 50 | +13 | +2 | 11 |
| 50 – 80 | +15 | +2 | 13 |
| 80 – 120 | +18 | +3 | 15 |
| 120 – 180 | +21 | +3 | 18 |
| 180 – 250 | +24 | +4 | 20 |
| 250 – 315 | +27 | +4 | 23 |
| 315 – 400 | +29 | +4 | 25 |
| 400 – 500 | +32 | +5 | 27 |
k5 for your nominal size
How k5 is built
An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter k sets the position of the tolerance zone; at Ø25 mm it lies entirely above the nominal size: the shaft is always larger than nominal. The number 5 is the standard tolerance grade IT5: it sets how wide the zone is – 9 µm at Ø25 mm.
The tolerance grows with the nominal size: 4 µm in the smallest row (0 – 3 mm), 27 µm in the largest (400 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 k5«; the inspection plan turns that into the limits 25.002 and 25.011 mm.
Fits with k5 at Ø25 mm
Hole-basis system: the hole is H, the shaft k5. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.
| Fit | Type | Max. clearance | Min. clearance |
|---|---|---|---|
| H6/k5 | transition fit | 11 | −11 |
Frequently asked questions about k5
What does k5 mean?
k5 is an ISO tolerance class for shafts (external features): the letter k sets the position of the tolerance zone, the number 5 the standard tolerance grade IT5. At Ø25 mm that gives +11 / +2 µm, i.e. 25.002 to 25.011 mm.
What are the k5 limits at Ø10 and Ø50 mm?
Ø10 k5: +7 / +1 µm (10.001 to 10.007 mm). Ø50 k5: +13 / +2 µm (50.002 to 50.013 mm).
Is k5 a clearance fit?
A tolerance class on its own is not a fit – only together with its mating part. H6/k5 at Ø25 mm is a transition fit (maximum clearance 11 µm, minimum clearance −11 µm; a minus means interference).
More tolerance classes
Same letter k, other grades: k6
Shafts in grade 5: h5 · g5 · js5 · m5 · n5
All classes at a glance: ISO 286 tolerance charts. The same chart in German: k5 Toleranz.