Bearing Size Chart: Find a Bearing by Bore, OD and Width

Quick bearing size chart

This table gives familiar examples from the 6000 and 6200 deep-groove ball bearing families. It is a fast starting point, not a complete catalog and not an interchange table.

Do not stop at the basic number. A 6204, 6204 ZZ, 6204 2RS and 6204 C3 may share nominal boundary dimensions, but their shields, seals or internal clearance are not the same.

Bearing size charts by series

These tables list the open (unsealed) basic numbers of the common deep groove ball bearing series. Every row links to its NLHB model page, where the shielded (ZZ) and sealed (2RS) versions and the dimension drawing are listed. Values are the same as on the model pages.

6000 series — extra-light (dimension series 10)

Same bore as the 6200 series, smaller outside diameter and width. Used where radial space is limited and loads are moderate.

6200 series — light (dimension series 02)

The most common general-purpose series: motors, pumps, gearboxes and appliances.

6300 series — medium (dimension series 03)

Same bore as the 6200 series, larger outside diameter and width, higher load ratings. The housing bore is larger.

6800 series — thin section (dimension series 18)

Very thin rings for compact designs. Load ratings are much lower than the 6000 series of the same bore.

6900 series — thin section (dimension series 19)

Between the 6800 and 6000 series in section height and load rating.

Miniature deep groove ball bearings (60x, 62x, 63x, 68x, 69x)

Bores from 3 to 9 mm. The second digit sets the section: 68x is the thinnest, then 69x, 60x, 62x and 63x. The same bore can therefore come in five outside diameters. Check all three dimensions; load ratings are on each model page.

Cr = basic dynamic load rating, C0r = basic static load rating, from the NLHB catalog dataset (the same values as each model page). Ratings differ between manufacturers for the same designation; use the rating of the bearing you actually buy for life calculations. In the 6000–6900 series, ZZ and 2RS versions normally share the open bearing's boundary dimensions. Many shielded miniature bearings are wider than the open version — always check the width on the model page or drawing.

What do d, D and B mean?

For the radial bearings covered by this lookup, d is the nominal bore diameter, D is the nominal outside diameter and B is the nominal bearing width. Other bearing types may use width or height symbols such as T, C or H. Always compare the measurement with the drawing for the correct bearing type.

ISO 15:2017 specifies preferred boundary dimensions for stated series of radial bearings. A boundary-dimension standard is not a universal interchange certificate.

How to find a bearing number from dimensions

1. Clean the bearing before measuring

Remove loose grease, dust, burrs and corrosion from the measuring surfaces. Dirt on a raceway face can shift a caliper reading enough to produce the wrong candidate list. Do not spin an unknown damaged bearing with compressed air.

2. Measure the bore diameter

Use the inside jaws of a calibrated vernier or digital caliper. Take more than one reading around the bore. A tapered, worn, split or sleeved bore needs more than one simple measurement.

3. Measure the outside diameter

Use the outside jaws and measure across the outer ring. Avoid a circlip, flange, rubber overmould or damaged area. Record special outer-ring features separately.

4. Measure the width

Measure between the bearing side faces. For a wide inner ring, insert bearing, track roller or double-row assembly, record the total width plus ring offsets and mounting features.

5. Search all three dimensions

Enter d × D × B in the NLHB Bearing Size Finder. The current tool searches within a visible ±0.5 mm tolerance for each entered dimension and returns candidates for further verification.

Metric or inch: keep the original measurement system

Not every bearing is designed around whole-millimetre dimensions. Agricultural, aircraft, textile, legacy American and special-equipment bearings may use inch dimensions or metric conversions with several decimal places. A bore near 12.7 mm may represent a nominal 1/2-inch bore rather than an inaccurate 13 mm metric bore.

1. Record the value exactly as measured.
2. Note whether the equipment, drawing or original catalog uses millimetres or inches.
3. Search the original unit first.
4. Keep converted values to at least three decimal places during identification.
5. Confirm the nominal unit and tolerance from the correct drawing.

A value such as 14.288 mm may be a converted 0.5625 inch dimension, not a nominal 14 mm bearing.

Why one size can return several bearing numbers

Consider 20 × 47 × 14 mm. In the NLHB public catalog dataset checked on August 13, 2026, this dimension set produces 12 candidates.

The replacement checklist after a size match

Bearing type and internal design

A deep-groove ball bearing and an angular-contact ball bearing can share boundary dimensions while behaving differently under axial load. Verify bearing type, number of rows, contact geometry and separability.

Full designation and suffixes

Record every letter, number, space and symbol on the rings, shields, seals and packaging. Suffix systems vary by manufacturer. Interpret familiar codes such as ZZ, 2RS, C3, P6 and cage codes against the relevant catalog.

Seals and shields

Metal shields and contact or non-contact rubber seals provide different balances of contamination protection, grease retention, friction and speed capability. Boundary dimensions cannot select the seal.

Internal clearance or preload

Clearance changes after fitting and at operating temperature. A tight shaft fit and thermal expansion can reduce operating clearance. Angular-contact or matched bearings may involve preload and arrangement-specific axial clearance.

Fits and mounting features

Check shaft and housing tolerances, shoulders, corner radii, snap-ring groove, flange, locking device and extended inner ring. A candidate can match d and D but still fail to seat correctly.

Load, speed and environment

Confirm radial and axial load, shock, duty cycle, speed, temperature, lubrication, moisture, dust, chemicals and electrical-current risk. Load ratings and speed references cannot be derived from d × D × B.

Precision, noise and documentation

Put tolerance class, vibration/noise group, material certificate, grease, traceability and inspection-report requirements on the inquiry. They cannot be assumed from the basic bearing number.

Read the candidate list in this order

What to send a supplier when the marking is unreadable

1. Measured d × D × B, original unit and measuring tool.
2. Clear photos of both faces, bore, outer ring and seals or shields.
3. Every readable marking and the original equipment model.
4. Bearing type or equipment location.
5. Radial and axial load information when available.
6. Operating speed, temperature and duty cycle.
7. Lubrication and contamination conditions.
8. Required quantity and whether a physical sample is available.

For a non-standard ring, groove, flange or extended width, add a toleranced sketch. See the custom bearing RFQ checklist before requesting a quotation.

When the answer may be a custom bearing

A catalog search can produce no suitable candidate because of wear, an integrated pulley or roller, a proprietary profile, an unusual groove, special internal geometry or a discontinued equipment-specific part. Do not force the nearest catalog number into the application. Preserve the sample, identify critical fits and functional surfaces, and separate must-match dimensions from features that may be redesigned for manufacturability.

Common lookup mistakes

Common problems and what the size chart tells you

A size chart cannot diagnose a failure, but it quickly shows whether the wrong series or size was fitted. Rule that out first, then check fits, clearance and lubrication.

Frequently asked questions