6204-RSR-NSK bearing: complete specifications & equivalents
The 6204-RSR-NSK is a ISO 15 radial bearing sized 20 x 47 x 14 mm (bore x OD x width) with RSR sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 20 mm |
| Outer diameter D | 47 mm |
| Width B | 14 mm |
| Material | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 14.1 kN |
| Basic static load rating C0 | 6.6 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 107 g |
| Manufacturer designation | NSK 6204VV |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
Dimensions in inches & 6200-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.551 in |
| ISO bore code | 04 |
| Radial section height (D−d)/2 | 13.5 mm |
| Smallest bore in 6200-series | 3 mm |
| Largest outer diameter in 6200-series | 540 mm |
| Width range across 6200-series | 2.5–85 mm |
| Bore position in 6200-series (smallest first) | 11 of 45 |
| Bore above smallest 6200-series size | 17 mm |
Mounting, lubrication & life for 6204-RSR-NSK
Recommended fits & mounting
- Rotating inner ring on a 20 mm shaft: k5; housing bore H7 for normal stationary-load outer rings. Reverse the logic if the outer ring rotates.
- Fit by induction heating (max 120 °C) where practical — never drive the ring home through the rolling elements.
- Keep shaft and housing fillet radii below the bearing chamfer so the 14 mm-wide ring seats square on its shoulder.
Lubrication strategy
Non-contact low-drag seal lips retain the factory grease but are not liquid-tight. Treat as grease-for-life in light, dry duty; in dirty or wet positions plan replacement around contamination rather than fatigue.
Worked L10 life example (illustrative duty)
For ball bearings, L10h = (C/P)3 · 106 / (60·n). Taking an example radial equivalent load P = 3 kN at n = 1,500 r/min (a small belted motor duty — substitute the real equivalent load from the application calculation):
C = 14.1 kN → L10h ≈ 1,154 hours — a warning that this section is lightly rated for a 3 kN load; a heavier section at the same 20 mm bore is the usual fix
Choosing a section at the same 20 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6004-FAG | 42 × 12 | 10.6 | 27,500 |
| 62xx | 6204-FAG | 47 × 14 | 14.7 | 24,300 |
| 63xx | 6304-FAG | 52 × 15 | 16.9 | 19,800 |
| 64xx | 6404-FAG | 72 × 19 | 30.5 | 14,000 |
| 618xx | 61804-FAG | 32 × 7 | 4.0 | 33,500 |
| 619xx | 61904-FAG | 37 × 9 | 6.4 | 28,500 |
| 160xx | 16004 | 42 × 8 | 7.9 | 26,000 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 20×47×14 envelope page. Match meaning, not the size chart alone: see what the cross-reference levels mean.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6204-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-RSR-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6204-RSR | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6204-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6204-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6204 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
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 6204-RSR-NSK model number is decoded
6204-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 47 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NSK's non-contact seal suffix is VV (catalogue number 6204VV), mapped here from the industry-neutral -RSR spelling; speed capability is close to the open bearing but VV is not liquid-tight.
Typical equipment & failure modes
Common applications
- small gearboxes
- conveyors and drives
- agricultural equipment
- fans and blowers
Known failure patterns
- ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
- lip-lubricant starvation if the bearing runs dry for extended periods
- 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
- Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6204-RSR-NSK.
- At 20 mm bore the 62xx light series is the workhorse section; its 47×14 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.
- The low-drag lip of 6204-RSR-NSK barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
- The non-contact lip of 6204-RSR-NSK does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 20 mm bore position before relying on it as sealed-for-life.
- Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.
- Shaft and housing fillets must clear the bearing chamfer so the 14 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- NSK catalogues this low-friction non-contact seal as 6204VV (suffix VV), mapped here from the industry-neutral -RSR spelling. NSK rates its speed capability close to the open bearing, but VV is not liquid-tight — for wet or fine-dust duty step up to the DDU contact seal (industry-neutral -2RS).
- The 20 mm bore puts 6204 in NSK's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty. NSK's VV non-contact seal is the high-speed choice here — DDU contact seal costs roughly 30–40% of the open-bearing speed ceiling.
- NSK rates 6204 at 14.1 kN dynamic (C) and 6.6 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
- At 107 g, 6204 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
- The 20×47×14 mm envelope of 6204 gives a D/d ratio of 2.35 and 13.5 mm radial section height — a heavy NSK section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
- The 14.1/6.6 kN load ratings, mass 107 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6204VV on the 20×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6204 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
- NSK supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.
- Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.
Frequently asked questions
What are the dimensions of a 6204-RSR-NSK bearing?
A 6204-RSR-NSK deep-groove ball bearing has a 20 mm bore, 47 mm outer diameter and 14 mm width (0.787 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
What internal clearance does 6204-RSR-NSK have?
Unless a clearance suffix says otherwise, 6204-RSR-NSK is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6204 and verify the residual clearance after mounting.
How should 6204-RSR-NSK be mounted?
Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What is the NSK suffix for a sealed 6204?
NSK uses suffix DDU for the contact rubber seal (catalogue number 6204VV), VV for the non-contact rubber seal, and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NSK suffixes while keeping the 20×47×14 mm ISO 15 envelope.
What is the difference between NSK VV and DDU seals?
VV is a non-contact rubber seal: low torque, speed close to the open bearing, dust-tight but not liquid-tight. DDU is a contact rubber seal: far better exclusion of moisture and fine dust, at the cost of a lower speed ceiling and higher running torque. 6204VV keeps the same ISO 15 envelope either way.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.