日本語

ISO fit calculator

Choose a nominal size and the hole and shaft tolerance classes to get the upper and lower deviations, the limits of size, the clearance or interference, and the type of fit. Values are ISO 286 / JIS B 0401 figures confirmed in at least two published sources such as manufacturers’ technical data.

Pick a hole and
a shaft to see
the fit.

Chips, the Kezuriba mascot

⊂⊃Fit calculator

—

Hole

Upper deviation ES
—
Lower deviation EI
—
Max. size
—
Min. size
—

Shaft

Upper deviation es
—
Lower deviation ei
—
Max. size
—
Min. size
—
Max. clearance—µm
Min. clearance—µm
Size range—mm

Max. clearance = ES − ei
Min. clearance = EI − es (negative = interference)

▤Preferred fits

Commonly used hole-basis and shaft-basis fits listed in JIS B 0401 (1998), the Japanese counterpart of ISO 286. Click a class to load that combination into the calculator above (* = exceptions in some size ranges).

Hole-basis fits

Basic holeClearanceTransitionInterference
H6g5h5js5k5m5
f6g6h6js6k6m6n6*p6*
H7f6g6h6js6k6m6n6p6*r6*s6t6u6x6
e7f7h7js7
H8f7h7
e8f8h8
d9e9
H9d8e8h8
c9d9e9h9
H10b9c9d9

Shaft-basis fits

Basic shaftClearanceTransitionInterference
h5H6JS6K6M6N6*P6
h6F6G6H6JS6K6M6N6P6*
F7G7H7JS7K7M7N7P7*R7S7T7U7X7
h7E7F7H7
F8H8
h8D8E8F8H8
D9E9H9
h9D8E8H8
C9D9E9H9
B10C10D10

Grey classes are not yet in this calculator. Sources: jp.misumi-ec.com, fujiikougyou.sakura.ne.jp, mikipulley.co.jp (the combinations match in all three).

Types of fit

holeshaftClearance fitholeshaftTransition fitholeshaftInterference fitnominal size
The dashed line is the nominal size; each box spans its limit deviations. Illustration only, not the values of any specific class — use the calculator above for real values.

Tables by tolerance class

Deviation tables up to 500 mm for each class (H7, h7, g6 …) are on the tolerance class list.

Notes

📚Sources

We compared the following technical documents that list ISO 286 / JIS B 0401 values and use values that agree in at least two of them. For S7, s6, no source with values above 250 mm was found, so those sizes are not calculated. For JS7 and js7, some sources write ±IT/2 (e.g. ±10.5) where IT7 is odd and others round down (e.g. ±10); this calculator uses ±IT/2.

  1. MISUMI
    jp.misumi-ec.com https://jp.misumi-ec.com/pdf/fa/2015/p1_2355.pdf
  2. NBK (Nabeya Bi-tech)
    fujiikougyou.sakura.ne.jp https://fujiikougyou.sakura.ne.jp/pdf/as.pdf
    fujiikougyou.sakura.ne.jp https://fujiikougyou.sakura.ne.jp/pdf/js.pdf
    fujiikougyou.sakura.ne.jp https://fujiikougyou.sakura.ne.jp/pdf/hma.pdf
  3. Mitsubishi Materials
    mitsubishicarbide.net https://www.mitsubishicarbide.net/contents/mhg/enuk/html/product/technical_infor…
    mitsubishicarbide.net https://www.mitsubishicarbide.net/contents/mhg/enuk/html/product/technical_infor…
  4. OSG
    osg.co.jp https://www.osg.co.jp/media_dl/technical/file/hameai.pdf
  5. Tungaloy
    tungaloy.com https://tungaloy.com/wpdata/wp-content/uploads/GC_2023-2024_J_UsersGuide.pdf
  6. Miki Pulley
    mikipulley.co.jp https://www.mikipulley.co.jp/jp/resources/standards-fitting-tolerances
    mikipulley.co.jp https://www.mikipulley.co.jp/jp/resources/common-shaft-hole-fits
  7. Tsubakimoto Chain
    tt-net.tsubakimoto.co.jp https://tt-net.tsubakimoto.co.jp/tecs/engd/kpl/engd_kpl_kyo.asp?lang=jp
  8. KHK (Kohara Gear)
    khkgears.co.jp https://www.khkgears.co.jp/gear_technology/gear_reference/khk488/
    khkgears.co.jp https://www.khkgears.co.jp/gear_technology/gear_reference/khk490/
  9. NSK
    nsk.com https://www.nsk.com/content/dam/nsk/jp/ja/catalogs/pdf/bearings/1103_parte.pdf
  10. Kyouiku Gear
    kggear.co.jp https://www.kggear.co.jp/wp-content/uploads/2021/02/technical-data.pdf