6203-ZZ-NTN bearing: complete specifications & equivalents
The 6203-ZZ-NTN 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 | NTN |
| Bore diameter d | 17 mm |
| Outer diameter D | 40 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 10.6 kN |
| Basic static load rating C0 | 4.6 kN |
| Fatigue load limit Pu | 0.35 kN |
| Limiting speed (mechanical) | 15000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 66 g |
| Manufacturer designation | 6203ZZ |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) |
| Last verified | 2026-09-25 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.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-NTN
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 = 10.6 kN → L10h ≈ 490 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-FAG | FAG | 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-FAG | FAG | 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-FAG | FAG | 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. |
| 6203-2RS-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-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 | 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-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 | 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 | 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. |
| 6203-2RS | 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. |
| 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-ZZ-NTN 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), 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. NTN catalogue order number: 6203ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.
Typical equipment & failure modes
Common applications
- large gearboxes
- industrial fans and blowers
- hoists and winches
- heavy conveyors
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
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- At 17 mm bore the ring mass is significant: heat 6203 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
- The 62xx light series is the default general-purpose section at 17 mm bore; before upgrading to a 6317 for extra capacity, confirm the housing accepts a 40 mm OD and 12 mm width — it is not a drop-in swap.
- ZZ shields are non-contact: 6203-ZZ-NTN 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-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
- 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.
- 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.
- NTN catalogues the shielded version as 6203ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.
- At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.
- NTN rates 6203 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.
- NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; 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 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 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 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203ZZ 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.
- NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.
- Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.
Frequently asked questions
What are the dimensions of a 6203-ZZ-NTN bearing?
A 6203-ZZ-NTN 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.
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 internal clearance does 6203-ZZ-NTN have?
Unless a clearance suffix says otherwise, 6203-ZZ-NTN 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 6203 and verify the residual clearance after mounting.
What is the NTN suffix for a sealed 6203?
NTN uses suffix LLU for the contact rubber seal (catalogue number 6203ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×40×12 mm ISO 15 envelope.
Does NTN offer 6203 with C3 clearance?
Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6203ZZ is the correct choice.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203-3/E (2024) on 2026-09-25. Read our editorial & correction policy.