Bearing Size Chart: Inch and Metric Bearing DimensionsCommon R-series and 6000-series bearing dimensions in inch and mm
Use this bearing size chart to look up common ball bearing bore, outside diameter, and width in both inches and millimeters. The chart includes representative inch R-series bearings and common metric 6000-series bearings for quick dimensional reference. Similar ID, OD, and width do not guarantee a safe or compatible replacement; always verify the manufacturer catalog, load rating, clearance, seal or shield type, tolerance class, lubrication, speed, and application conditions.
ID / OD / Width Lookup
Compare bearing bore, outside diameter, and width without switching between inch and metric tables.
Inch and Metric Units
See inch-series dimensions converted to millimeters and metric-series dimensions converted to decimal inches.
Interchange Caveats
Use dimensions as a starting point only; replacement decisions require catalog and application checks.
Answer first: bearing ID, OD, and width in inch and mm
Answer first: bearing size charts usually compare three dimensions: bore or inside diameter (ID), outside diameter (OD), and width. For example, an R8 inch-series bearing is commonly listed as 1/2 in ID, 1-1/8 in OD, and 5/16 in width, which converts to about 12.700 mm × 28.575 mm × 7.938 mm. A 6001 metric bearing is commonly listed as 12 mm ID, 28 mm OD, and 8 mm width, or about 0.4724 in × 1.1024 in × 0.3150 in. These dimensions are reference values only and do not prove interchangeability.
Dimension reference only: do not choose a replacement bearing by ID, OD, and width alone. Verify the exact manufacturer catalog data, load rating, internal clearance, seal or shield type, tolerance class, lubrication, speed rating, and operating conditions.
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Showing 20 bearing rows. On small screens, swipe the table horizontally to see all columns.
Bearing dimension chart
Search common inch R-series and metric 6000-series rows. The table is crawlable HTML text and uses 1 inch = 25.4 mm for conversions.
| Bearing ↑ | Series | Bore / ID (in) | Bore / ID (mm) | OD (in) | OD (mm) | Width (in) | Width (mm) | Notes |
|---|---|---|---|---|---|---|---|---|
| 6000 | Metric 6000-series | 0.3937 in | 10 mm | 1.0236 in | 26 mm | 0.3150 in | 8 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6001 | Metric 6000-series | 0.4724 in | 12 mm | 1.1024 in | 28 mm | 0.3150 in | 8 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6002 | Metric 6000-series | 0.5906 in | 15 mm | 1.2598 in | 32 mm | 0.3543 in | 9 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6003 | Metric 6000-series | 0.6693 in | 17 mm | 1.3780 in | 35 mm | 0.3937 in | 10 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6004 | Metric 6000-series | 0.7874 in | 20 mm | 1.6535 in | 42 mm | 0.4724 in | 12 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6005 | Metric 6000-series | 0.9843 in | 25 mm | 1.8504 in | 47 mm | 0.4724 in | 12 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6006 | Metric 6000-series | 1.1811 in | 30 mm | 2.1654 in | 55 mm | 0.5118 in | 13 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6007 | Metric 6000-series | 1.3780 in | 35 mm | 2.4409 in | 62 mm | 0.5512 in | 14 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6008 | Metric 6000-series | 1.5748 in | 40 mm | 2.6772 in | 68 mm | 0.5906 in | 15 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6009 | Metric 6000-series | 1.7717 in | 45 mm | 2.9528 in | 75 mm | 0.6299 in | 16 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| 6010 | Metric 6000-series | 1.9685 in | 50 mm | 3.1496 in | 80 mm | 0.6299 in | 16 mm | Metric-series dimensional reference; suffixes such as ZZ, 2RS, C3, and tolerance class can change suitability even when dimensions match. |
| R2 | Inch R-series | 1/8 (0.1250 in) | 3.175 mm | 3/8 (0.3750 in) | 9.525 mm | 5/32 (0.1563 in) | 3.969 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R3 | Inch R-series | 3/16 (0.1875 in) | 4.762 mm | 1/2 (0.5000 in) | 12.700 mm | 0.196 (0.1960 in) | 4.978 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R4 | Inch R-series | 1/4 (0.2500 in) | 6.350 mm | 5/8 (0.6250 in) | 15.875 mm | 0.196 (0.1960 in) | 4.978 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R6 | Inch R-series | 3/8 (0.3750 in) | 9.525 mm | 7/8 (0.8750 in) | 22.225 mm | 9/32 (0.2813 in) | 7.144 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R8 | Inch R-series | 1/2 (0.5000 in) | 12.700 mm | 1-1/8 (1.1250 in) | 28.575 mm | 5/16 (0.3125 in) | 7.938 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R10 | Inch R-series | 5/8 (0.6250 in) | 15.875 mm | 1-3/8 (1.3750 in) | 34.925 mm | 11/32 (0.3438 in) | 8.731 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R12 | Inch R-series | 3/4 (0.7500 in) | 19.050 mm | 1-5/8 (1.6250 in) | 41.275 mm | 7/16 (0.4375 in) | 11.112 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R14 | Inch R-series | 7/8 (0.8750 in) | 22.225 mm | 1-7/8 (1.8750 in) | 47.625 mm | 1/2 (0.5000 in) | 12.700 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
| R16 | Inch R-series | 1 (1.0000 in) | 25.400 mm | 2 (2.0000 in) | 50.800 mm | 1/2 (0.5000 in) | 12.700 mm | Inch-series dimensional reference; verify exact suffix, clearance, shield/seal, load rating, and manufacturer catalog before replacement. |
Do not use ID, OD, and width alone as a replacement rule. Check the exact part number, suffix, load rating, clearance, seal or shield type, tolerance class, lubrication, speed, and application conditions.
How to read ID, OD, and width
Bore / inside diameter
The shaft-side opening, also called bearing ID.
Outside diameter
The diameter of the bearing outer ring.
Width
The bearing thickness across the ring faces. These dimensions identify possible size families but do not confirm interchange.
Why matching dimensions is not enough for interchange
Two bearings can share the same ID, OD, and width while having different load ratings, internal clearance, shield or seal designs, materials, cage construction, tolerance classes, lubrication, and speed limits. A suffix such as ZZ, 2RS, C3, ABEC, or a manufacturer-specific code can change whether a bearing fits the application. Treat this chart as a lookup aid, then confirm the final part in the manufacturer catalog.
Common bearing dimension examples
Use these examples for quick lookup, then verify suffixes, catalog data, load, speed, clearance, seal/shield, and application conditions.
R8 bearing dimensions
R8 is commonly listed as 1/2 in ID, 1-1/8 in OD, and 5/16 in width, approximately 12.700 × 28.575 × 7.938 mm.
Dimension reference onlyR6 bearing dimensions
R6 is commonly listed as 3/8 in ID, 7/8 in OD, and 9/32 in width, approximately 9.525 × 22.225 × 7.144 mm.
Dimension reference only6001 bearing dimensions
6001 is commonly listed as 12 × 28 × 8 mm, approximately 0.4724 × 1.1024 × 0.3150 in.
Dimension reference only6004 bearing dimensions
6004 is commonly listed as 20 × 42 × 12 mm, approximately 0.7874 × 1.6535 × 0.4724 in.
Dimension reference onlyData and rounding assumptions
- Inch conversion: mm = inch × 25.4.
- Metric conversion: inch = mm ÷ 25.4.
- Rounding: Inch-source rows show common fractions plus converted millimeters to 3 decimals. Metric-source rows show source millimeters and converted decimal inches to 4 decimals.
- Reference scope: Dimension values are representative reference dimensions for common bearing designations and are converted with 1 inch = 25.4 mm.
- Last reviewed: 2026-07-06.
Important bearing selection note
This chart is a dimensional reference for bore, outside diameter, and width. Similar dimensions do not guarantee a safe or compatible replacement. Bearing interchange also depends on load rating, internal clearance, cage and material, seal or shield type, tolerance class, lubrication, speed rating, operating temperature, shaft and housing fits, and the actual application conditions. Always verify the exact manufacturer catalog and engineering requirements before selecting a bearing.
Bearing size chart FAQ
What does a bearing size chart show?
A bearing size chart shows the main physical dimensions of a bearing, usually bore or inside diameter, outside diameter, and width. This page shows those dimensions in inches and millimeters for representative inch R-series and metric 6000-series bearings.
What do ID, OD, and width mean on a bearing?
ID, or bore, is the inside diameter that fits over the shaft. OD is the outside diameter of the outer ring. Width is the bearing thickness across the ring faces.
Can I replace a bearing if the ID, OD, and width match?
Not by dimensions alone. Matching ID, OD, and width is only a starting point. You also need to verify load rating, internal clearance, seal or shield type, tolerance class, lubrication, speed rating, and application conditions in the manufacturer catalog.
Are inch R-series bearings interchangeable with metric 6000-series bearings?
Do not assume they are interchangeable. Some inch and metric bearings may look dimensionally close, but dimensional similarity does not prove a safe replacement or equal performance.
How do you convert bearing dimensions from inches to millimeters?
Multiply the inch dimension by 25.4. For example, a 1/2 inch bore converts to 12.700 mm because 0.5 × 25.4 = 12.7.
How do you convert bearing dimensions from millimeters to inches?
Divide the millimeter dimension by 25.4. For example, a 12 mm bore is about 0.4724 inches because 12 ÷ 25.4 = 0.4724.
Do bearing suffixes like ZZ, 2RS, or C3 matter?
Yes. Suffixes can describe shields, seals, internal clearance, tolerance, lubrication, or other construction details. Two bearings with the same base dimensions can behave differently if their suffixes or specifications differ.
Is this chart a load rating or bearing life calculator?
No. This chart is only a dimensional reference. Bearing load rating, life, speed, lubrication, and application suitability must be checked with manufacturer data and engineering requirements.
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