Deep groove ball bearing · 618 series (thin section)
61820 bearing
100 × 125 × 13 mm
The 61820 is a deep groove ball bearing with a 100 mm bore, 125 mm outside diameter and 13 mm width. Very thin section for compact designs and large hollow shafts.
- Bore d
- 100 mm 3.937 in
- Outside diameter D
- 125 mm 4.9213 in
- Width B
- 13 mm 0.5118 in
- Dimension series
- 18
- Load directions
- Radial and moderate axial in both directions
Designation explained
What 61820 means
Standard bearing numbers encode the type, the dimension series and the bore. Anything after the base number — seals, clearance, cage — is a suffix.
| Part | Meaning |
|---|---|
6 | Deep groove ball bearing |
1 | Diameter series 1 (undefined), dimension series 18 |
20 | 20 → 100 mm bore (20 × 5) |
Variants
Common 61820 variants
Suffixes change the bearing without changing its boundary dimensions. The exact letters differ between manufacturers — always order by the full designation from the maker you choose.
| Suffix | Example | Meaning |
|---|---|---|
Z / ZZ (2Z) | 61820-ZZ | Metal shield on one / both sides; keeps out coarse dirt, low friction |
RS / 2RS | 61820-2RS | Rubber contact seal on one / both sides; better protection against dust and water |
C2 | 61820-C2 | Internal radial clearance smaller than normal |
CN (no suffix) | 61820 | Normal internal clearance |
C3 | 61820-C3 | Internal clearance greater than normal — common for electric motors and heated shafts |
C4 | 61820-C4 | Internal clearance greater than C3 |
| Manufacturer | Shields both sides | Contact seals both sides |
|---|---|---|
| SKF | 61820-2Z | 61820-2RS1 |
| FAG (Schaeffler) | 61820-2Z | 61820-2RSR |
| NSK | 61820-ZZ | 61820-DDU |
| NTN | 61820-ZZ | 61820-LLU |
| Koyo (JTEKT) | 61820-ZZ | 61820-2RS |
61820-2RS (sealed)
- Rubber contact seals on both sides
- Best protection against dust, water and grease loss
- Slightly more friction and a lower speed limit
- Choose for dirty, wet or outdoor use
61820-ZZ / 2Z (shielded)
- Metal shields on both sides, small gap to the inner ring
- Keeps out coarse dirt; not water-tight
- Lower friction, higher speeds
- Choose for clean, fast-running applications
Same bore
Other 100 mm bore bearings
Every standard bearing in this reference with a 100 mm bore, from light to heavy sections.
| Designation | Type | D | B / H |
|---|---|---|---|
| 6020 | Deep groove ball bearing | 150 mm | 24 mm |
| 6220 | Deep groove ball bearing | 180 mm | 34 mm |
| 6320 | Deep groove ball bearing | 215 mm | 47 mm |
| 61920 | Deep groove ball bearing | 140 mm | 20 mm |
| 1220 | Self-aligning ball bearing | 180 mm | 34 mm |
| 1320 | Self-aligning ball bearing | 215 mm | 47 mm |
| 2220 | Self-aligning ball bearing | 180 mm | 46 mm |
| 2320 | Self-aligning ball bearing | 215 mm | 73 mm |
| 7220 | Angular contact ball bearing | 180 mm | 34 mm |
| 7320 | Angular contact ball bearing | 215 mm | 47 mm |
| NU220 | Cylindrical roller bearing | 180 mm | 34 mm |
| NU320 | Cylindrical roller bearing | 215 mm | 47 mm |
| NU2220 | Cylindrical roller bearing | 180 mm | 46 mm |
| NU2320 | Cylindrical roller bearing | 215 mm | 73 mm |
| 22220 | Spherical roller bearing | 180 mm | 46 mm |
| 22320 | Spherical roller bearing | 215 mm | 73 mm |
| 30220 | Tapered roller bearing | 180 mm | 37 mm |
| 30320 | Tapered roller bearing | 215 mm | 51.5 mm |
| 32020X | Tapered roller bearing | 150 mm | 32 mm |
| 32220 | Tapered roller bearing | 180 mm | 49 mm |
| 51120 | Thrust ball bearing | 135 mm | 25 mm |
| 51220 | Thrust ball bearing | 150 mm | 38 mm |
| 51320 | Thrust ball bearing | 170 mm | 55 mm |
Where to buy
Find 61820 at sellers
Search results on independent sellers. We are not affiliated with them, do not earn from these links and do not see their prices or stock. Results mix brands and variants — check the full designation before you order.
About these dimensions. Boundary dimensions follow ISO 15 (radial bearings — boundary dimensions, general plan), dimension series 18, and are the same for every manufacturer of a standard 61820. Chamfers, load ratings, speed limits and weight depend on the manufacturer and design and are not shown — use the maker's datasheet for engineering decisions. Last checked 9 October 2026. Spotted an error? Tell us.
Learn more
What size is a 61820 bearing?
A 61820 is a deep groove ball bearing with a 100 mm bore, 125 mm outside diameter and 13 mm width (100 × 125 × 13 mm). These boundary dimensions follow the ISO dimension plan, so they are the same across manufacturers.
What does 61820-2RS or 61820-ZZ mean?
Same size, different closures: 2RS has rubber contact seals on both sides, ZZ (2Z) has metal shields on both sides. Manufacturers use different letters for the same idea — for example NSK DDU or NTN LLU for contact seals.
Can I replace 61820 with another bearing of the same size?
Other bearing types can share the same 100 × 125 × 13 mm envelope, but a different type has different load directions, speed limits and mounting needs. Same dimensions alone do not make two bearings interchangeable.
Where are the load ratings and speed limits?
They depend on the manufacturer and internal design, so we do not list a single value. Check the datasheet for the exact full designation you intend to use.
Need 61820 data for a whole catalog?
We can help with that.
Normalized specifications, variants and supplier listings for every bearing you sell, with the source behind each value.