6218-ZZ bearing: complete specifications & equivalents
The 6218-ZZ is a ISO 15 radial bearing sized 90 x 160 x 30 mm (bore x OD x width) with ZZ sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 90 mm |
| Outer diameter D | 160 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | ZZ |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 101 kN |
| Basic static load rating C0 | 73.5 kN |
| Fatigue load limit Pu | 2.8 kN |
| Reference speed (thermal) | 8500 rpm |
| Limiting speed (mechanical) | 4300 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 2300 g |
| Manufacturer designation | SKF 6218-2Z |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 6200-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.181 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 6200-series | 10 mm |
| Largest outer diameter in 6200-series | 400 mm |
| Width range across 6200-series | 9–65 mm |
| Bore position in 6200-series (smallest first) | 19 of 33 |
| Bore above smallest 6200-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6218 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range. Brand-specific OEM equivalents pending multi-source data. |
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 6218-ZZ model number is decoded
In the 6200-series (ISO 15 diameter series 2) the last two digits encode the bore: 6218 carries bore code 18 = 90 mm. Outside diameter 160 mm and width 30 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 90 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. SKF's own suffix is 2Z (this page's industry-neutral spelling is -ZZ); catalogue number 6218-2Z.
Typical equipment & failure modes
Common applications
- industrial fans and blowers
- hoists and winches
- heavy conveyors
- pulp and paper machinery
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
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Mount this 90 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 62xx light series is the default general-purpose section at 90 mm bore; before upgrading to a 6318 for extra capacity, confirm the housing accepts a 160 mm OD and 30 mm width — it is not a drop-in swap.
- ZZ shields are non-contact: 6218-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6218-2RS for that.
- Shielded 6218-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.
- Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- SKF spells the shielded version 6218-2Z (one shield: 6218-Z), not "-ZZ": the suffix language differs by brand even though the ISO envelope is identical, so quote the brand designation when ordering.
- The single-shield execution 6218-Z is a distinct order number in catalogue 17000: it suits open gears or oil-bath arrangements where the unshielded face faces the lubricant, and it is not interchangeable with the double-shield 6218-2Z for high-contamination positions.
- The 101/73.5 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6218-ZZ bearing?
A 6218-ZZ deep-groove ball bearing has a 90 mm bore, 160 mm outer diameter and 30 mm width (3.543 × 6.299 × 1.181 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields. Geometry-based estimated mass is about 2104 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 6218 bore code work?
The last two digits of 6218 are bore code 18, giving 18 × 5 = 90 mm bore. The 160 mm outside diameter and 30 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the ZZ suffix on 6218-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 6200 compare with other series at the same 90 mm bore?
The '2' is the light diameter series: 160×30 mm with a 35.0 mm radial section at 90 mm bore. A 6318 on the same bore is larger and higher-rated; a 6018 is smaller and lower-rated.
What is the SKF designation and catalogue data for 6218-ZZ?
In the SKF Rolling Bearings catalogue this size is listed as 6218-2Z — two non-contact sheet-metal shields, 90×160×30 mm per ISO 15. Quoted values: C 101 kN, C0 73.5 kN, Pu 2.8 kN, limiting speed 4300 r/min, mass 2300 g. Brand suffixes (2Z, 2RSH) differ from the industry-neutral spelling 6218-ZZ.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.