6921 Bearing Dimensions
The ENRO 6921 is a deep groove ball bearing in the 6900 series, 105 × 145 × 20 mm. Boundary dimensions follow the ISO 15 dimension series.
Three checks for the 6921
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 6921 is 105 × 145 × 20 mm. If one value differs, see the adjacent sizes below.
Adjacent sizes →Which version do you need?
ENRO lists 3 versions: 6921, 6921-ZZ, 6921-2RS. Match the seals, shields or bore type of the old bearing.
Versions table →Is the load rating enough?
Cr 42.7 kN, C0r 41.9 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 69216921 dimensions and ratings
| Bore diameterd | 105 mm |
|---|---|
| Outside diameterD | 145 mm |
| WidthB | 20 mm |
| Chamfer dimension, min.r min | 1.1 mm |
| Basic dynamic load ratingCr | 42.7 kN |
| Basic static load ratingC0r | 41.9 kN |
| Limiting speed, greasen grease | 4,000 rpm |
| Limiting speed, oiln oil | 5,000 rpm |
| Weight (approx.)m | 0.870 kg |
| Series | 6900 |
| 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 “6921” means
- 69 — bearing type and dimension series code.
- 21 — bore code: code 21 × 5 = 105 mm.
6921 variants: 6921 / 6921-ZZ / 6921-2RS
| Order as | Meaning |
|---|---|
| 6921 | Open. No shields or seals. Lubricated in service by grease or oil. |
| 6921-ZZ | Metal shields, both sides. Non-contact steel shields. Low friction; keeps out larger particles. |
| 6921-2RS | Rubber seals, both sides. Contact rubber seals. Better protection against dust and water; slightly higher friction. |
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.
Selection notes for the 6921
How this size sits against its neighbours in the 6900 series and the other deep groove ball bearing series with the same bore. Every figure is from the ENRO model table.
- The 6921 is the twenty-second of twenty-eight sizes ENRO lists in the 6900 series, 105 × 145 × 20 mm.
- Next size down, the 6920, is 100 × 140 × 20 mm: five millimetres less bore, five millimetres less outside diameter, the same width.
- Next size up, the 6922, is 110 × 150 × 20 mm: five millimetres more bore, five millimetres more outside diameter, the same width.
- Five other ENRO deep groove ball bearings share the 105 mm bore: the 6821 (6800 series) is 130 × 13 mm, fifteen millimetres less outside diameter and seven millimetres narrower; the 6021 (6000 series) is 160 × 26 mm, fifteen millimetres more outside diameter and six millimetres wider.
- The 6921 has a radial section of 20 mm ((D − d) / 2) on a 20 mm width, so its cross-section is square.
- Catalog reference values for the 6921: Cr 42.7 kN, C0r 41.9 kN, limiting speed 4,000 rpm with grease, 5,000 rpm with oil, weight 0.870 kg.
- Catalog dynamic load rating Cr is 42.7 kN for the 6921 against 36.90 kN for the 6920 (noticeably less, 5.8 kN or 14%) and 43.6 kN for the 6922 (marginally more, 0.9 kN or 2%).
- ENRO lists the 6921 in three versions: 6921, 6921-ZZ, 6921-2RS. In the same series, the 6920 is listed adding snap ring groove with snap ring; the 6922 is listed in the same three versions.
6921 bearing dimensions: range and series
28 sizes in the 6900 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 |
|---|---|---|---|---|---|---|---|---|
| 6917 | 85 | 120 | 18 | 28.80 | 28.42 | 5,100 | 0.550 | |
| 6918 | 90 | 125 | 18 | 29.70 | 30.24 | 4,800 | 0.585 | |
| 6919 | 95 | 130 | 18 | 30.15 | 32.16 | 4,600 | 0.601 | |
| 6920 | 100 | 140 | 20 | 36.90 | 37.92 | 4,300 | 0.828 | |
| 6921 | 105 | 145 | 20 | 42.7 | 41.9 | 4,000 | 0.870 | This page |
| 6922 | 110 | 150 | 20 | 43.6 | 44.4 | 3,600 | 0.900 | |
| 6924 | 120 | 165 | 22 | 57.2 | 56.9 | 3,400 | 1.200 | |
| 6926 | 130 | 180 | 24 | 65.1 | 67.2 | 3,000 | 1.600 | |
| 6928 | 140 | 190 | 24 | 66.6 | 71.2 | 2,800 | 1.589 |
Catalog reference values. Full 6900 series table →
If the 6921 is not quite right
Nearest ENRO sizes by bore and by series. Check the housing and shaft before switching.
Other series with a 105 mm bore
Click a model to open its full specification page.
| Model | Series | d | D | B | Cr kN | Open model page |
|---|---|---|---|---|---|---|
| 6921 | 6900 | 105 | 145 | 20 | 42.7 | This page |
| 6821 | 6800 | 105 | 130 | 13 | On request | |
| 6021 | 6000 | 105 | 160 | 26 | 72.50 | |
| 6221 | 6200 | 105 | 190 | 36 | 133.00 | |
| 6321 | 6300 | 105 | 225 | 49 | 184.00 | |
| 6421 | 6400 | 105 | 260 | 60 | 207.00 |
Same 145 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 6921: 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 6921
- 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 6921Engineering tools built on our catalog data
6921 FAQ
What are the dimensions of the 6921 deep groove ball bearing?
The 6921 has a bore (d) of 105 mm, an outside diameter (D) of 145 mm and a width (B) of 20 mm. Minimum chamfer r is 1.1 mm.
What load rating does the 6921 have?
Catalog reference values: basic dynamic load rating Cr 42.7 kN, static rating C0r 41.9 kN, limiting speed 4,000 rpm with grease. Values are confirmed per batch on request.
Which versions of the 6921 can I order?
ENRO lists the 6921 as 6921 (Open), 6921-ZZ (Metal shields, both sides), 6921-2RS (Rubber seals, both sides). State the clearance group you need in your RFQ.
Is the ENRO 6921 interchangeable with other brands' 6921?
Boundary dimensions follow the ISO 15 dimension series. The ENRO 6921 is dimensionally interchangeable with other brands' 6921 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 6921-ZZ and 6921-2RS?
6921-ZZ has metal shields, both sides: Non-contact steel shields. Low friction; keeps out larger particles. 6921-2RS 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 6921?
In the ENRO range, 6821 (105 × 130 × 13 mm), 6021 (105 × 160 × 26 mm), 6221 (105 × 190 × 36 mm), 6321 (105 × 225 × 49 mm) share the 105 mm bore. Outside diameter and width differ, so check the housing before switching.
Which clearance group should I order for the 6921?
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 6921?
Deep Groove Ball Bearings are classified under HS Code 8482.10. Confirm the code with your customs broker.
Quote the 6921
Send any part number and we'll match the dimensionally equivalent ENRO model. We reply within 24 hours on business days.