Bearing Number to Dimensions Converter
Convert standard bearing numbers to inner diameter, outer diameter, and width in mm and inches.
Covers 6000, 6200, 6300, and 600 series deep groove ball bearings.
Select a bearing number — see its dimensions.
Standard ball bearing numbers follow an ISO numbering system that encodes the bearing series, bore size, and type. The most common type is the deep groove ball bearing, identified by the 6000 series prefix.
How bearing numbers work: A bearing number like 6205 breaks down as follows: the first digit (6) indicates deep groove ball bearing type. The second digit (2) indicates the dimension series, which defines the ratio of outer diameter to width. The last two digits (05) indicate the bore size. For bearings 04 and above, multiply the last two digits by 5 to get the bore diameter in millimeters. So 6205 has a bore of 05 x 5 = 25 mm.
Special bore codes for small bearings:
- 00 = 10 mm bore
- 01 = 12 mm bore
- 02 = 15 mm bore
- 03 = 17 mm bore
- 04 and above = last two digits x 5
Common bearing dimension series:
- 600 series (e.g., 608): Extra light, narrow width. Popular in skateboards, small motors, and 3D printers.
- 6000 series (e.g., 6005): Light series, moderate load capacity. Used in pumps, fans, and small gearboxes.
- 6200 series (e.g., 6205): Medium series, higher load capacity. The most widely used series for industrial motors, conveyors, and automotive applications.
- 6300 series (e.g., 6305): Heavy series, maximum load capacity for a given bore size. Used in heavy machinery, large motors, and high-load applications.
Suffix codes indicate special features:
- ZZ or 2Z: Metal shields on both sides (keeps dust out)
- 2RS or 2RSR: Rubber seals on both sides (keeps grease in, contaminants out)
- C3: Greater than normal internal clearance (for high temperature or interference fit)
- NR: Snap ring groove on outer ring
Choosing the right bearing: Match the bore to your shaft diameter. Select the series based on load requirements: use 6000 for light loads, 6200 for moderate loads, and 6300 for heavy loads. Always consider speed ratings, as smaller cross-section bearings (6000 series) generally allow higher speeds than larger ones (6300 series) for the same bore size.
Bearing tolerances: Standard bearings (no prefix) follow ABEC-1 or ISO P0 tolerances. Higher precision classes include ABEC-3 (P6), ABEC-5 (P5), ABEC-7 (P4), and ABEC-9 (P2). Higher precision means tighter dimensional tolerances and smoother rotation, but also higher cost.