6203-ZZ bearing: complete specifications & equivalents
The 6203-ZZ is a ISO 15 radial bearing sized 17 x 40 x 12 mm (bore x OD x width) with ZZ sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 40 mm |
| Width B | 12 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 | 9.95 kN |
| Basic static load rating C0 | 4.75 kN |
| Fatigue load limit Pu | 0.2 kN |
| Reference speed (thermal) | 38000 rpm |
| Limiting speed (mechanical) | 19000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 68 g |
| Manufacturer designation | SKF 6203-2Z |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-25 |
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 | 0.669 in |
|---|---|
| Outer diameter D | 1.575 in |
| Width B | 0.472 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 11.5 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) | 10 of 45 |
| Bore above smallest 6200-series size | 14 mm |
Mounting, lubrication & life for 6203-ZZ
Recommended fits & mounting
- Rotating inner ring on a 17 mm shaft: j5; 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 12 mm-wide ring seats square on its shoulder.
Lubrication strategy
Non-contact metal shields block coarse debris while running nearly as cool as open. No relubrication path on the standard execution; the shield cavity grease ages even though the steel is still serviceable.
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 = 9.9 kN → L10h ≈ 405 hours — a warning that this section is lightly rated for a 3 kN load; a heavier section at the same 17 mm bore is the usual fix
Choosing a section at the same 17 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6003-FAG | 35 × 10 | 6.4 | 31,000 |
| 62xx | 6203-FAG | 40 × 12 | 11.0 | 29,000 |
| 63xx | 6303-FAG | 47 × 14 | 15.8 | 24,500 |
| 64xx | 6403-FAG | 62 × 17 | 23.8 | 16,200 |
| 618xx | 61803-FAG | 26 × 5 | 2.2 | 41,500 |
| 619xx | 61903-FAG | 30 × 7 | 4.6 | 34,500 |
| 160xx | 16003 | 35 × 8 | 6.0 | 31,000 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 17×40×12 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 |
|---|---|---|---|
| 6203-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6203-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6203-ZZ-FAG | FAG | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6203 | 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 before substituting. |
| 6203-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6203-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6203-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6203-ZZ-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6203-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6203-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 6203-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (ZZ vs RSR) — confirm sealing suits the duty. |
| 6203-ZZ-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 7203 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| W6203-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6203-2RS1 shares the 17×40×12 mm envelope but rates differently (9.95/4.75 kN vs 8.06/4.75 kN) — not a load-rating equivalent. |
| W6203-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6203-2Z shares the 17×40×12 mm envelope but rates differently (9.95/4.75 kN vs 8.06/4.75 kN) — not a load-rating equivalent. |
| W6203 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6203 shares the 17×40×12 mm envelope but rates differently (9.95/4.75 kN vs 8.06/4.75 kN) — not a load-rating equivalent. |
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 6203-ZZ model number is decoded
6203-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the light 62xx section (diameter series 2 of ISO 15), its bore code 03 comes from the 10/12/15/17 mm exception table, giving a 17 mm bore; the 40 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's own suffix is 2Z (this page's industry-neutral spelling is -ZZ); catalogue number 6203-2Z.
Typical equipment & failure modes
Common applications
- instrument drives
- fractional-horsepower electric motors
- domestic appliances
- power tools
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
- 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
- Bore codes 00–03 use the exception table: 6203 fits a 17 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- At 17 mm bore the 62xx light series is the workhorse section; its 40×12 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.
- ZZ shields are non-contact: 6203-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6203-2RS for that.
- Shielded 6203-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.
- The housing bore for the 40 mm OD should be round within IT7; an oval bore pinches the outer ring of 6203-ZZ and shows up later as two-point loaded raceway wear.
- Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 12 mm-wide ring of 6203-ZZ drags the lip and overheats it.
- SKF spells the shielded version 6203-2Z (one shield: 6203-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 6203-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 6203-2Z for high-contamination positions.
- The 9.95/4.75 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 6203-ZZ bearing?
A 6203-ZZ deep-groove ball bearing has a 17 mm bore, 40 mm outer diameter and 12 mm width (0.669 × 1.575 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields.
What does the ZZ suffix on 6203-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 17 mm bore?
The '2' is the light diameter series: 40×12 mm with an 11.5 mm radial section at 17 mm bore. A 6303 on the same bore is larger and higher-rated; a 6003 is smaller and lower-rated.
Are 6203 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6203 uses the same ISO 15 envelope (17×40×12 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, 2RSL and similar).
What is the SKF designation and catalogue data for 6203-ZZ?
In the SKF Rolling Bearings catalogue this size is listed as 6203-2Z — two non-contact sheet-metal shields, 17×40×12 mm per ISO 15. Quoted values: C 9.95 kN, C0 4.75 kN, Pu 0.2 kN, limiting speed 19000 r/min, mass 68 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6203-ZZ.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-25. Read our editorial & correction policy.