6203-2RS-FAG bearing: complete specifications & equivalents
The 6203-2RS-FAG is a ISO 15 radial bearing sized 17 x 40 x 12 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | FAG |
| Bore diameter d | 17 mm |
| Outer diameter D | 40 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 11 kN |
| Basic static load rating C0 | 4.75 kN |
| Limiting speed (mechanical) | 16900 rpm |
| Mass | 66 g |
| Manufacturer designation | FAG 6203-C-2HRS |
| Standard | ISO 15 |
| Catalog version | HR 1 Rolling Bearings (Jan 2020) |
| Last verified | 2026-09-25 |
Source: catalog reference (HR 1 Rolling Bearings (Jan 2020)) · extracted 2026-09-25
Parameters extracted from the official FAG Rolling Bearings catalogue (HR 1 Rolling Bearings (Jan 2020)); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.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 6203-2RS-FAG
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
Contact-sealed execution: greased and sealed for life, no relubrication path. Grease life — not steel fatigue — usually sets the replacement interval; rising running temperature or noise near the end of service is the practical trigger.
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 = 11.0 kN → L10h ≈ 548 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-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 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 and load ratings may differ — confirm sealing and rating before substituting. |
| 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 and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-2RS-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 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 and load ratings may differ — confirm sealing and rating before substituting. |
| 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 and load ratings may differ — confirm sealing and rating before substituting. |
| 6203 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6203-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6203-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6203-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6203 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×40×12 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 6203-2RS-FAG model number is decoded
6203-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 17 by five gives the 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. Schaeffler HR 1 catalogues the lip-contact sealed version as 6203-C-2HRS (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.
Typical equipment & failure modes
Common applications
- large gearboxes
- industrial fans and blowers
- hoists and winches
- heavy conveyors
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- false brinelling from vibration while the shaft is stationary
- fretting corrosion on a loose shaft seat
Selection pitfalls — read before you substitute
- Large bores like the 17 mm of 6203-2RS-FAG demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
- 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.
- Contact seals add drag and heat: 6203-2RS-FAG runs slower and cooler-limited than the open 6203; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Never wash a sealed 6203-2RS-FAG in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Never mix components between two 6203-2RS-FAG units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- Vibration during standstill brinells the raceways of a 17 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.
- Schaeffler HR 1 lists the lip-contact sealed version as 6203-C-2HRS (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. FAG's RSR lip material is NBR as standard — above roughly 100 °C continuous, consult Schaeffler for higher-temperature seal options.
- FAG rates 6203 at 16900 r/min mechanical limiting speed — electric-motor territory; prefer the open or 2Z execution (sealed 2RSR variants lose roughly a third of the thermal speed) and confirm grease life at the reference speed for continuous running.
- At 17 mm bore the 6203 sits in Schaeffler's small-bore range; HR 1 ships these sizes with a pressed steel or plastic cage and P0 tolerance as standard — for instrument or spindle accuracy order the P6/P5 variant explicitly, since P0 runout figures will not hold.
- FAG rates 6203 at 11 kN dynamic (C) and 4.75 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — verify the equivalent dynamic load stays well below C for conveying or gearbox duty with shock.
- At 66 g, 6203 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 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy FAG section 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 11/4.75 kN load ratings, mass 66 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 6203-C-2HRS on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive. Where FAG has since released an X-life version of this size, its expanded C/C0 ratings supersede the HR 1 print values quoted here.
- FAG sealed units arrive greased for life with a lithium-soap fill; Schaeffler quotes a shelf life for greased bearings and recommends running stock first-in-first-out rather than re-greasing aged sealed units.
- Mixing old and new FAG generations of the same designation in one arrangement is dimensionally acceptable, but where ratings matter — preloaded or matched sets — order both positions from the same generation and lot.
Frequently asked questions
What are the dimensions of a 6203-2RS-FAG bearing?
A 6203-2RS-FAG 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 contact rubber seals and is normally pre-greased.
How does the 6203 bore code work?
The last two digits of 6203 are bore code 17, giving 17 × 5 = 17 mm bore. The 40 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone.
What does the 2RS suffix on 6203-2RS mean?
2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling.
What is the FAG suffix for a sealed 6203?
FAG uses suffix 2RSR for the lip-contact rubber seal (catalogue number 6203-C-2HRS), 2RZ for the non-contact rubber seal and 2Z for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those FAG suffixes while keeping the 17×40×12 mm ISO 15 envelope.
What is the difference between FAG 2RZ and 2RSR seals?
2RZ is a non-contact rubber seal: minimal drag, speed close to the open bearing, not liquid-tight. 2RSR is a lip-contact seal: better protection against moisture and fine dust at the cost of speed and torque. Both keep the ISO 15 envelope of 6203-C-2HRS.
Reviewed & verified by the MPN Base engineering desk against source catalog HR 1 Rolling Bearings (Jan 2020) on 2026-09-25. Read our editorial & correction policy.