Upper and lower deviations of hole H7 for nominal sizes 0–500 mm, per ISO 286-1. Values in mm; "+" means larger than nominal, "-" smaller. Calculate other sizes →
| Nominal size (mm) | Upper deviation | Lower deviation | Tolerance (IT) |
|---|---|---|---|
| 0 ~ 3 | +0.010 | 0 | 0.010 |
| >3 ~ 6 | +0.012 | 0 | 0.012 |
| >6 ~ 10 | +0.015 | 0 | 0.015 |
| >10 ~ 18 | +0.018 | 0 | 0.018 |
| >18 ~ 30 | +0.021 | 0 | 0.021 |
| >30 ~ 50 | +0.025 | 0 | 0.025 |
| >50 ~ 80 | +0.030 | 0 | 0.030 |
| >80 ~ 120 | +0.035 | 0 | 0.035 |
| >120 ~ 180 | +0.040 | 0 | 0.040 |
| >180 ~ 250 | +0.046 | 0 | 0.046 |
| >250 ~ 315 | +0.052 | 0 | 0.052 |
| >315 ~ 400 | +0.057 | 0 | 0.057 |
| >400 ~ 500 | +0.063 | 0 | 0.063 |
Each row applies to the whole size range shown. Ranges are "over the first value, up to and including the second".
H7 is an ISO 286 tolerance class. The uppercase letter H is the fundamental deviation (which side of the nominal size the tolerance zone lies on), and the number 7 is the tolerance grade IT7 (how wide the zone is). Basic hole (zero-clearance sliding): The lower deviation is 0, so the hole is never smaller than nominal. It is the datum of the hole-basis system; holes made with reamers and drills are naturally H. H7 is the most common hole tolerance: dowel pin holes, bushing bores, bearing housings. Typical processes for IT7: fine turning, reaming, fine boring: the usual grade for fitted holes (H7) and h7 dowel pins.
On a drawing or in a specification, Ø6 H7 and 6(+0.012/0) mean the same thing — the second form writes the deviations out, so nobody has to look them up. SFP product specifications always use the second form.
Click "Calc" in the last column to open the calculator, where the written-out form can be copied with one click.
| Size | Upper deviation | Lower deviation | Actual limits (mm) | |
|---|---|---|---|---|
| Ø1 | +0.010 | 0 | 1.000 ~ 1.010 | Calc |
| Ø1.5 | +0.010 | 0 | 1.500 ~ 1.510 | Calc |
| Ø2 | +0.010 | 0 | 2.000 ~ 2.010 | Calc |
| Ø2.5 | +0.010 | 0 | 2.500 ~ 2.510 | Calc |
| Ø3 | +0.010 | 0 | 3.000 ~ 3.010 | Calc |
| Ø4 | +0.012 | 0 | 4.000 ~ 4.012 | Calc |
| Ø5 | +0.012 | 0 | 5.000 ~ 5.012 | Calc |
| Ø6 | +0.012 | 0 | 6.000 ~ 6.012 | Calc |
| Ø8 | +0.015 | 0 | 8.000 ~ 8.015 | Calc |
| Ø10 | +0.015 | 0 | 10.000 ~ 10.015 | Calc |
| Ø12 | +0.018 | 0 | 12.000 ~ 12.018 | Calc |
| Ø13 | +0.018 | 0 | 13.000 ~ 13.018 | Calc |
| Ø16 | +0.018 | 0 | 16.000 ~ 16.018 | Calc |
| Ø20 | +0.021 | 0 | 20.000 ~ 20.021 | Calc |
| Ø25 | +0.021 | 0 | 25.000 ~ 25.021 | Calc |
| Ø30 | +0.021 | 0 | 30.000 ~ 30.021 | Calc |
| Ø35 | +0.025 | 0 | 35.000 ~ 35.025 | Calc |
| Ø40 | +0.025 | 0 | 40.000 ~ 40.025 | Calc |
| Ø50 | +0.025 | 0 | 50.000 ~ 50.025 | Calc |
| Ø60 | +0.030 | 0 | 60.000 ~ 60.030 | Calc |
| Ø80 | +0.030 | 0 | 80.000 ~ 80.030 | Calc |
| Ø100 | +0.035 | 0 | 100.000 ~ 100.035 | Calc |
| Fit | Type | Typical use |
|---|---|---|
| H7/g6 | Clearance | Precision sliding fit: very small clearance, slides freely with almost no play. Precision guides, reciprocating piston rods and guide bushings, dowel pins and fixture holes that are plugged in and out often yet must stay centred. |
| H7/h6 | Clearance | Sliding / locational fit with zero minimum clearance; can be assembled by hand. Stationary joints that must be centred, or slow sliding: removable dowel pins in fixture holes, couplings on shafts, replaceable guide bushings. |
| H7/js6 | Transition | The loosest transition fit, averaging close to zero clearance. Assembled by hand or with a mallet; for parts that must be centred yet removable: gears and pulleys on shafts (torque carried by a key). |
| H7/k6 | Transition | The most widely used transition fit, with a small chance of interference. Assembled with light hammer blows, removable and well centred: gears, pulleys, couplings, rolling-bearing inner rings on shafts (light loads). |
| H7/m6 | Transition | A transition fit on the tight side, mostly a slight interference. The standard pairing for press-in dowel pins — ISO 8734 / DIN 6325 plus-tolerance pins are m6, used with a reamed H7 hole; for moulds, dies and fixtures that are rarely dismantled and must not work loose. |
| H7/n6 | Transition | The tightest transition fit, almost always an interference. Needs a press and is not normally dismantled: fixed pins, bushings, gear rims. |
| H7/p6 | Interference | Light interference: held by pressing in but unable to transmit much torque on its own (add a key). Bushings pressed into housings, locating sleeves, heavily loaded bearing outer rings in housings. |
| H7/r6 | Interference | Medium interference: transmits moderate torque, assembled with a press; dismantling damages the parts. |
| H7/s6 | Interference | Medium interference: transmits a certain torque and axial force; assembled with a press or by heating. Permanent joints of steel and cast-iron parts, gear rims on hubs. |
| H7/u6 | Interference | Heavy interference: shrink or expansion fit; the interference transmits high torque and the joint is regarded as permanent. Railway wheels on axles, heavy-duty couplings. |
| H7/f7 | Clearance | Close running fit. Plain bearings at medium speed and load, gearbox shafts and bushings, rotating parts that need an oil film. |
The tolerance zones of the classes below lie entirely inside H7 (true for every size range from 0 to 500 mm), so they also satisfy a drawing that calls for H7. Those listed first are closest to H7; price and lead time still depend on material, size and stock.
It depends on the diameter. For Ø6, H7 means the part must measure between 6.000 and 6.012 mm, written 6(+0.012/0). For other diameters see the chart above; every size range is listed.
Letters in uppercase denote a hole (inside diameter). In lowercase, h7 is a shaft tolerance, lying on the opposite side of the nominal size.
Yes. H6 is tighter than H7: at every diameter its limits fall inside the range H7 allows. The precision is simply higher than required, so the price may be a little higher.
Values follow ISO 286-1; the table was cross-checked cell by cell against three independent sources on 2026-08-26 (6,674 cells agree, 0 errors). Coverage: shafts a–z and the corresponding uppercase holes, IT1–IT13, nominal sizes 0–500 mm. cd/ef/fg/za/zb/zc, sizes above 500 mm and grades above IT13 are not included: the tool reports "not found" and never extrapolates. Data sources and verification →