6308 Bearing Dimensions
The ENRO 6308 is a deep groove ball bearing in the 6300 series, 40 × 90 × 23 mm. Typical applications: Industrial motors, conveyors. Boundary dimensions follow the ISO 15 dimension series.
Three checks for the 6308
Most wrong replacements come from one of these. Each answer below comes from the ENRO model table.
Does the size match?
Measure bore, outside diameter and width. The 6308 is 40 × 90 × 23 mm. If one value differs, see the adjacent sizes below.
Adjacent sizes →Which version do you need?
ENRO lists 4 versions: 6308, 6308-ZZ, 6308-2RS, 6308-NR. Match the seals, shields or bore type of the old bearing.
Versions table →Is the load rating enough?
Cr 36.45 kN, C0r 23.04 kN (catalog reference values). Check the life at your load and speed.
Life calculator →Not sure which one you have? Send any part number and we'll match the dimensionally equivalent ENRO model.
Check my 63086308 dimensions and ratings
| Bore diameterd | 40 mm |
|---|---|
| Outside diameterD | 90 mm |
| WidthB | 23 mm |
| Chamfer dimension, min.r min | 1.5 mm |
| Basic dynamic load ratingCr | 36.45 kN |
| Basic static load ratingC0r | 23.04 kN |
| Limiting speed, greasen grease | 7,400 rpm |
| Limiting speed, oiln oil | 8,700 rpm |
| Weight (approx.)m | 0.636 kg |
| Series | 6300 |
| HS code | 8482.10 |
| Material | GCr15 chrome steel |
| Precision class | P0, P6 |
| Cage | Steel, nylon |
| Clearance group | C0 (CN), C3 |
| Origin | Made in China — Japanese-standard quality management |
Load ratings, limiting speeds and weights are catalog reference values. Values are confirmed per batch on request.
What “6308” means
- 63 — bearing type and dimension series code.
- 08 — bore code: code 08 × 5 = 40 mm.
6308 variants: 6308 / 6308-ZZ / 6308-2RS / 6308-NR
| Order as | Meaning |
|---|---|
| 6308 | Open. No shields or seals. Lubricated in service by grease or oil. |
| 6308-ZZ | Metal shields, both sides. Non-contact steel shields. Low friction; keeps out larger particles. |
| 6308-2RS | Rubber seals, both sides. Contact rubber seals. Better protection against dust and water; slightly higher friction. |
| 6308-NR | Snap ring groove with snap ring. Snap ring on the outer ring for axial location in the housing. |
State the clearance group per line on your RFQ. Suffix selector →
Print or save this table as PDF, or ask us to send the spec sheet with your quote.
Where the 6308 is used
Positions ENRO lists for this size, the versions to name on the RFQ and what to check first.
Typical applications
Industrial motors, conveyors. These are the positions ENRO lists for the 6308; confirm against the marking on the bearing being replaced.
Versions to ask for
6308 (open), 6308-ZZ (metal shields, both sides), 6308-2RS (rubber seals, both sides), 6308-NR (snap ring groove with snap ring). Open, shielded (ZZ), sealed (2RS) or snap ring (NR).
What to check before ordering
Bore, outside diameter and width: 40 × 90 × 23 mm. Shield or seal type and the clearance group (CN or C3) of the old bearing. Catalog Cr 36.45 kN against your load; run the life calculator if the position is loaded.
Selection notes from the table
- The 6308 is the twelfth of thirty-one sizes ENRO lists in the 6300 series, 40 × 90 × 23 mm.
- Next size down, the 6307, is 35 × 80 × 21 mm: five millimetres less bore, ten millimetres less outside diameter, two millimetres narrower.
- Next size up, the 6309, is 45 × 100 × 25 mm: five millimetres more bore, ten millimetres more outside diameter, two millimetres wider.
- Six other ENRO deep groove ball bearings share the 40 mm bore: the 6208 (6200 series) is 80 × 18 mm, ten millimetres less outside diameter and five millimetres narrower; the 6408 (6400 series) is 110 × 27 mm, twenty millimetres more outside diameter and four millimetres wider.
- The 6308 has a radial section of 25 mm ((D − d) / 2) on a 23 mm width, so its cross-section is taller than it is wide.
- Catalog reference values for the 6308: Cr 36.45 kN, C0r 23.04 kN, limiting speed 7,400 rpm with grease, 8,700 rpm with oil, weight 0.636 kg.
- Catalog dynamic load rating Cr is 36.45 kN for the 6308 against 30.15 kN for the 6307 (noticeably less, 6.3 kN or 17%) and 47.70 kN for the 6309 (substantially more, 11.25 kN or 31%).
- ENRO lists the 6308 in four versions: 6308, 6308-ZZ, 6308-2RS, 6308-NR. In the same series, the 6307 is listed in the same four versions; the 6309 is listed in the same four versions.
6308 bearing dimensions: range and series
31 sizes in the 6300 series.
Click a model to open its full specification page.
| Model | d mm | D mm | B mm | Cr kN | C0r kN | Grease rpm | Weight kg | Open model page |
|---|---|---|---|---|---|---|---|---|
| 63/28 | 28 | 68 | 18 | 24.03 | 13.44 | 10,000 | 0.287 | |
| 6306 | 30 | 72 | 19 | 24.03 | 14.40 | 9,500 | 0.345 | |
| 63/32 | 32 | 75 | 20 | 26.82 | 16.22 | 9,000 | 0.389 | |
| 6307 | 35 | 80 | 21 | 30.15 | 18.34 | 8,400 | 0.464 | |
| 6308 | 40 | 90 | 23 | 36.45 | 23.04 | 7,400 | 0.636 | This page |
| 6309 | 45 | 100 | 25 | 47.70 | 30.72 | 6,700 | 0.829 | |
| 6310 | 50 | 110 | 27 | 55.80 | 36.39 | 6,100 | 1.060 | |
| 6311 | 55 | 120 | 29 | 64.35 | 43.20 | 5,500 | 1.370 | |
| 6312 | 60 | 130 | 31 | 73.80 | 49.92 | 5,100 | 1.720 |
Catalog reference values. Full 6300 series table →
If the 6308 is not quite right
Nearest ENRO sizes by bore and by series. Check the housing and shaft before switching.
Other series with a 40 mm bore
Click a model to open its full specification page.
| Model | Series | d | D | B | Cr kN | Open model page |
|---|---|---|---|---|---|---|
| 6308 | 6300 | 40 | 90 | 23 | 36.45 | This page |
| 6808 | 6800 | 40 | 52 | 7 | 4.59 | |
| 6908 | 6900 | 40 | 62 | 12 | 13.14 | |
| 16008 | 16000 | 40 | 68 | 9 | 11.34 | |
| 6008 | 6000 | 40 | 68 | 15 | 15.12 | |
| 6208 | 6200 | 40 | 80 | 18 | 26.19 | |
| 6408 | 6400 | 40 | 110 | 27 | 63.50 |
Same 90 mm outside diameter, different bore
Click a model to open its full specification page.
Specifications and boundary dimensions
Built to be checked, not believed. Boundary dimensions follow the ISO 15 dimension series. Ratings follow ISO 281 and clearance groups ISO 5753-1; every value on a model page can be checked against the standard.
Boundary dimensions
Boundary dimensions follow the ISO 15 dimension series. Same base number, same d, D and B.
Tolerances
Defines the tolerance classes for radial bearings. State the class you need on the RFQ.
Internal clearance
Defines the clearance groups C2, CN, C3, C4 and C5. State the group you need on the RFQ.
Rating life
Basis of the L10 basic rating life. Use it with the catalog Cr in our life calculator.
Japan-managed quality control
ENRO is a bearing brand for distributors and MRO buyers. Our QC protocol follows Japanese industrial quality practice. Our bearings are made in China.
100% outgoing inspection
Every ENRO bearing — not a sample, every unit — passes outgoing inspection before shipment.
Same color, same box, same label
Every order ships in the same color box with the same label, so repeat shipments match on the shelf.
How to order the 6308: packing and marking
- Version
- Open, shielded (ZZ), sealed (2RS) or snap ring (NR).
- Clearance group
- CN, C3 or another group. State it per line.
- Quantity per line
- Quantities per model and whether the order repeats.
- Marking options
- ENRO packing, OEM / private label or neutral packaging. State which one per line.
- Destination
- Port or country the order ships to.
Free samples are available.
Get a quote for a 6308
- Model or part number for each line
- Quantity per line
- Seal or shield, snap ring or bore type
- Clearance group, if not CN
- Destination port or country
We reply within 24 hours on business days.
Quote 6308Engineering tools built on our catalog data
6308 FAQ
What is the 6308-2Z bearing?
It is a 6308 with metal shields, both sides (2Z and ZZ are two ways of writing the same shield arrangement). ENRO designates it 6308-ZZ. The 6308 has a bore (d) of 40 mm, an outside diameter (D) of 90 mm and a width (B) of 23 mm. Minimum chamfer r is 1.5 mm.
What type of bearing is the 6308 C3?
C3 is an internal clearance group larger than normal (CN) under ISO 5753-1. A 6308 C3 has the same boundary dimensions as a standard 6308. Specify C3 in your RFQ.
What are the dimensions of the 6308 deep groove ball bearing?
The 6308 has a bore (d) of 40 mm, an outside diameter (D) of 90 mm and a width (B) of 23 mm. Minimum chamfer r is 1.5 mm.
What load rating does the 6308 have?
Catalog reference values: basic dynamic load rating Cr 36.45 kN, static rating C0r 23.04 kN, limiting speed 7,400 rpm with grease. Values are confirmed per batch on request.
Which versions of the 6308 can I order?
ENRO lists the 6308 as 6308 (Open), 6308-ZZ (Metal shields, both sides), 6308-2RS (Rubber seals, both sides), 6308-NR (Snap ring groove with snap ring). State the clearance group you need in your RFQ.
Is the ENRO 6308 interchangeable with other brands' 6308?
Boundary dimensions follow the ISO 15 dimension series. The ENRO 6308 is dimensionally interchangeable with other brands' 6308 of the same size. Confirm seal, clearance and cage requirements in your RFQ.
Where are ENRO bearings made?
ENRO bearings are Made in China by partner factories, under Japan-managed quality control. Every unit passes 100% outgoing inspection before shipment.
What is the difference between 6308-ZZ and 6308-2RS?
6308-ZZ has metal shields, both sides: Non-contact steel shields. Low friction; keeps out larger particles. 6308-2RS has rubber seals, both sides: Contact rubber seals. Better protection against dust and water; slightly higher friction. Boundary dimensions are the same.
Which bearings have the same bore as the 6308?
In the ENRO range, 6808 (40 × 52 × 7 mm), 6908 (40 × 62 × 12 mm), 16008 (40 × 68 × 9 mm), 6008 (40 × 68 × 15 mm) share the 40 mm bore. Outside diameter and width differ, so check the housing before switching.
Which clearance group should I order for the 6308?
CN (normal) suits most positions. C3 is common where the inner ring runs warmer than the outer ring, as in electric motors. Groups are defined in ISO 5753-1; state the one you need in your RFQ.
What is the HS code for the 6308?
Deep Groove Ball Bearings are classified under HS Code 8482.10. Confirm the code with your customs broker.
Quote the 6308
Send any part number and we'll match the dimensionally equivalent ENRO model. We reply within 24 hours on business days.