6420 bearing: complete specifications & equivalents
The 6420 is a ISO 15 radial bearing sized 100 x 250 x 58 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 100 mm |
| Outer diameter D | 250 mm |
| Width B | 58 mm |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Mass (geometry estimate) | 12203 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 6420 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 6400-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 9.843 in |
| Width B | 2.283 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 75 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) | 21 of 21 |
| Bore above smallest 6400-series size | 90 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6420 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) 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 6420 model number is decoded
In the 6400-series (ISO 15 diameter series 4) the last two digits encode the bore: 6420 carries bore code 20 = 100 mm. Outside diameter 250 mm and width 58 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 100 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
- industrial fans and blowers
- hoists and winches
- heavy conveyors
- pulp and paper machinery
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Mount this 100 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 100 mm bore (250 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.
- The open 6420 has no lubricant retention: grease escapes and contaminants migrate straight into the 100×250×58 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6420 units.
- A 100 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 6420 bearing?
A 6420 deep-groove ball bearing has a 100 mm bore, 250 mm outer diameter and 58 mm width (3.937 × 9.843 × 2.283 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields. Geometry-based estimated mass is about 12203 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
How does the 6420 bore code work?
The last two digits of 6420 are bore code 20, giving 20 × 5 = 100 mm bore. The 250 mm outside diameter and 58 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 6420 mean?
A bare 6420 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 6400 compare with other series at the same 100 mm bore?
The '4' is the heavy diameter series: 250×58 mm, 75.0 mm radial section at 100 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts.
Are 6420 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6420 uses the same ISO 15 envelope (100×250×58 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting.
Reviewed & verified by the MPN Base engineering desk against source catalog iso15-ed4-geometry on 2026-09-24. Read our editorial & correction policy.