Bearing size chart

Deep groove ball

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Angular contact ball

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Self-aligning ball

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Thrust ball

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Cylindrical roller

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Tapered roller

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Spherical roller

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Needle roller

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Linear

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Spherical plain

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

Pillow block insert

Nominal ISO boundary dimensions for reference. Confirm against your drawing and the supplier datasheet.

How to use the size tables

The finder and the tables above list the nominal boundary dimensions of common standard series, in millimetres. Choose the bearing type, then enter the bore, the outside diameter or the width you know. Any two dimensions usually narrow the field to one or two designations. Treat the figures as reference values: they are nominal ISO boundary dimensions, and the final check is always the drawing and the supplier datasheet that goes with the quote.

If you only have a worn part, measure the three dimensions before looking anything up. A pair of calipers is enough; how to measure a bearing shows where to place them and why an old, worn bore reads slightly large.

What the letters mean

A bearing can carry the same bore in several series. The extra information that tells them apart is the dimension series.

Dimension series

ISO 15 groups radial bearings by two things: a width series and a diameter series. The second is the one that decides the outside diameter for a given bore. Series 8 and 9 are thin, 0 and 1 are extra light, 2 is light, 3 is medium and 4 is heavy. Within deep groove ball bearings, the 62 series is the most common general series, 63 uses larger balls for higher load, and 60, 68 and 69 save radial space. For the same 25 mm bore, you can find 6805, 6905, 6005, 6205 and 6305, each with a different outside diameter and width. They all fit a 25 mm shaft but need different housings. See deep groove ball bearings.

Bore codes

The last two digits of a designation are the bore code. For 04 and above, multiply by five to get the bore in millimetres: 08 means 40 mm, 12 means 60 mm, 20 means 100 mm. The small bores are fixed: 00 is 10 mm, 01 is 12 mm, 02 is 15 mm and 03 is 17 mm. Bores below 10 mm are normally written directly, as in 608 for 8 mm. Bores of 500 mm and above are written after a slash instead of using the multiply-by-five rule. The designation guide covers the whole code.

Common reading mistakes

Four errors account for most wrong-size orders. The first is mixing up the bore code and the series: 6305 is not a 6205 with a thicker ring, it is a different series with the same 25 mm bore. The second is reading a worn bore from an old part, which is slightly oversized. The third is measuring the outside diameter of a part with a seal or snap ring groove and taking the groove edge as the ring. The fourth is assuming that a tapered bore and a cylindrical bore of the same nominal size are the same part; the K suffix changes the arrangement, as explained in bearing accessories. When in doubt, send photos with a ruler in frame and the desk will help read them.

Searching by size

1. Pick the type: deep groove, tapered roller, cylindrical roller, spherical roller, needle, thrust and so on.
2. Enter bore and outside diameter; if several rows remain, check width.
3. Read the designation from the row and note whether it is a different series with the same bore.
4. Confirm clearance, tolerance class, seals and cage in the full designation.
5. Send the designation and quantity through the quote form.

Inch sizes and non-standard dimensions

The tables cover metric standard series only. Inch-size bearings, especially tapered roller bearings with inch cones and cups, follow their own system and are not listed here. If you need inch parts, send the part number or measure bore, outside diameter and width in both millimetres and inches, and the desk checks availability against partner plant ranges. Many inch and metric dimensions look alike but are not interchangeable, so a near match is not a match.

If your size is not in any standard series, it may be a special part. Send a drawing or a sample. Non-standard sizes are assessed from the drawing; typical reference ranges for them are in custom bearings and MOQ and lead time, always confirmed in writing for each program.