6418-ZZ bearing: complete specifications & equivalents
The 6418-ZZ is a ISO 15 radial bearing sized 90 x 225 x 54 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 | 225 mm |
| Width B | 54 mm |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Mass (geometry estimate) | 9203 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 6418 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 6400-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 8.858 in |
| Width B | 2.126 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 67.5 mm |
| Smallest bore in 6400-series | 10 mm |
| Largest outer diameter in 6400-series | 250 mm |
| Width range across 6400-series | 12–58 mm |
| Bore position in 6400-series (smallest first) | 19 of 21 |
| Bore above smallest 6400-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6418 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 90×225×54 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — 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 6418-ZZ model number is decoded
In the 6400-series (ISO 15 diameter series 4) the last two digits encode the bore: 6418 carries bore code 18 = 90 mm. Outside diameter 225 mm and width 54 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.
Typical equipment & failure modes
Common applications
- medium and heavy industrial drives
- large gearboxes
- industrial fans and blowers
- hoists and winches
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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- brinelling from static overload or hammering during mounting
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 64xx heavy section at 90 mm bore (225 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.
- ZZ shields are non-contact: 6418-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6418-2RS for that.
- Shielded 6418-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.
- A 90 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
Frequently asked questions
What are the dimensions of a 6418-ZZ bearing?
A 6418-ZZ deep-groove ball bearing has a 90 mm bore, 225 mm outer diameter and 54 mm width (3.543 × 8.858 × 2.126 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields. Geometry-based estimated mass is about 9203 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 6418 bore code work?
The last two digits of 6418 are bore code 18, giving 18 × 5 = 90 mm bore. The 225 mm outside diameter and 54 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the ZZ suffix on 6418-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 6400 compare with other series at the same 90 mm bore?
The '4' is the heavy diameter series: 225×54 mm, 67.5 mm radial section at 90 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts.
Are 6418 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6418 uses the same ISO 15 envelope (90×225×54 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.