61810-ZZ bearing: complete specifications & equivalents
The 61810-ZZ is a ISO 15 radial bearing sized 50 x 65 x 7 mm (bore x OD x width) with ZZ sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 50 mm |
| Outer diameter D | 65 mm |
| Width B | 7 mm |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Mass (geometry estimate) | 48 g |
| Standard | ISO 15 |
| Catalog version | iso15-ed4-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 61810 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 61800-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 2.559 in |
| Width B | 0.276 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 7.5 mm |
| Smallest bore in 61800-series | 10 mm |
| Largest outer diameter in 61800-series | 420 mm |
| Width range across 61800-series | 5–38 mm |
| Bore position in 61800-series (smallest first) | 11 of 39 |
| Bore above smallest 61800-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61810 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×65×7 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 61810-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×65×7 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 61810-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×65×7 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 61810-ZZ model number is decoded
In the 61800-series (ISO 15 diameter series 8) the last two digits encode the bore: 61810 carries bore code 10 = 50 mm. Outside diameter 65 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
Known failure patterns
- fine-particle abrasion when non-contact shields let dust past in dirty duty
- grease aging in the shield-for-life cavity with no relubrication path
- brinelling from static overload or hammering during mounting
- false brinelling from vibration while the shaft is stationary
Selection pitfalls — read before you substitute
- Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61810 with C3 for those conditions.
- The 618xx thin section at 50 mm bore has only a 7.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.
- ZZ shields are non-contact: 61810-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61810-2RS for that.
- Shielded 61810-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
- Suffixes stack in a defined order — clearance follows the seal code, e.g. 61810-ZZ-C3. No clearance suffix means normal CN clearance.
Frequently asked questions
What are the dimensions of a 61810-ZZ bearing?
A 61810-ZZ deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields. Geometry-based estimated mass is about 48 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 61810 bore code work?
The last two digits of 61810 are bore code 10, giving 10 × 5 = 50 mm bore. The 65 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the ZZ suffix on 61810-ZZ mean?
ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing.
How does the 61800 compare with other series at the same 50 mm bore?
618 is an extra-thin section: 65×7 mm, only 7.5 mm radial section at 50 mm bore, far smaller than a 6210, for space-limited layouts at the cost of load rating and misalignment tolerance.
Are 61810 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61810 uses the same ISO 15 envelope (50×65×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU and similar).
Reviewed & verified by the MPN Base engineering desk against source catalog iso15-ed4-geometry on 2026-09-24. Read our editorial & correction policy.