6203 bearing: complete specifications & equivalents
The 6203 is a ISO 15 radial bearing sized 17 x 40 x 12 mm (bore x OD x width). 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 | open |
| 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) | 24000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 65 g |
| Manufacturer designation | SKF 6203 |
| 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
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
Open execution: the application supplies lubrication. Use the grease relubrication chart for this bearing — pitch diameter dm = 28.5 mm, so the speed factor at the 24,000 r/min limiting speed is 684,000 mm·r/min. Intervals shorten steeply as that factor rises.
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 (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6203-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-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 6203 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 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 (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6203-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-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 (OPEN vs RSR) — confirm sealing suits the duty. |
| 6203-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 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 (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6203-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. |
| 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 (OPEN vs RSR) — confirm sealing suits the duty. |
| 6203-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 7203 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 1726203-2RS1 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 1726203-2RS1 is a standard-inner-ring insert on the same 17x40x12 mm ISO 15 envelope with ratings within 10 %, but its outer surface is sphered for a Y-housing whereas this page is the cylindrical-OD deep-groove bearing — not interchangeable mounts. |
| 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 model number is decoded
6203 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. 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. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.
Typical equipment & failure modes
Common applications
- instrument drives
- fractional-horsepower electric motors
- domestic appliances
- power tools
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
- 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.
- The open 6203 has no lubricant retention: grease escapes and contaminants migrate straight into the 17×40×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6203 units.
- 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.
- Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- The open 6203 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6203-2Z (shields) and 6203-2RSH (contact seals), not suffix-free 6203.
- 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 bearing?
A 6203 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 an open bearing with no seals or shields.
What does no suffix on 6203 mean?
A bare 6203 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 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.
What is the SKF designation and catalogue data for 6203?
In the SKF Rolling Bearings catalogue this size is listed as 6203 — the open (unsealed) execution, 17×40×12 mm per ISO 15. Quoted values: C 9.95 kN, C0 4.75 kN, Pu 0.2 kN, limiting speed 24000 r/min, mass 65 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6203.
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.