32203 bearing: complete specifications & equivalents
The 32203 is a ISO 355 radial bearing sized 17 x 40 x 17.25 mm (bore x OD x width). 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 | 17.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 30.5 kN |
| Basic static load rating C0 | 28.3 kN |
| Limiting speed (mechanical) | 9900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 102 g |
| Manufacturer designation | NTN 32203 |
| Standard | ISO 355 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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 & 32200-series range
| Bore d | 0.669 in |
|---|---|
| Outer diameter D | 1.575 in |
| Width B | 0.679 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 11.5 mm |
| Smallest bore in 32200-series | 17 mm |
| Largest outer diameter in 32200-series | 580 mm |
| Width range across 32200-series | 17.25–159 mm |
| Bore position in 32200-series (smallest first) | 1 of 36 |
| Bore above smallest 32200-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32203 | 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. |
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 32203 model number is decoded
32203 belongs to the NTN metric 4T tapered roller range (heavy-section 32200 family); the open bearing leaves sealing to the application and is normally ordered and mounted as an adjustable matched pair. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32203 resolves to 17 mm bore; the NTN factory mark 4T is stamped on cone and cup but is a brand mark, not a size code, so the catalogue sku is printed without it. NTN adjusts these bearings by cup or cone position rather than shipping a preloaded set; the mounting drawing must state end play or preload for 32203, since running clearance is set during assembly. Selection: C 30.5 kN against C0 28.3 kN gives a C0/C ratio of 0.93 for the 17 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Open 4T bearings need application seals; without them the grease at the cone rib of 32203 washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- scooter and light-powersport wheel and gear positions
- small conveyor pulley shafts
- steering-knuckle and kingpin positions
- small automotive wheel hubs and trailer axles
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- At 17 mm bore the thin section and small rollers are adjustment-sensitive: a quarter-turn of the locknut moves end play by more than on large bearings, so set the 32203 pair with a dial indicator rather than by feel.
- The heavy-section 32200 family at 17 mm bore (40×17.25 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 13,000 r/min oil ceiling.
- ISO 355 makes the 17×40 mm envelope interchangeable but not the ratings: NTN prints 30.5/28.3 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 17 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 17 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 30.5/28.3 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32203 (ISO 355 2DD); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 32203?
32203 is a metric 4T tapered roller bearing to ISO 355: 17 mm bore, 40 mm outside diameter and 17.25 mm assembled width T (0.669 × 1.575 × 0.679 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 30.5 kN, C0 28.3 kN (2203E prints no Pu for this size), grease limiting speed 9,900 r/min, oil speed 13,000 r/min, mass about 102 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32203?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (32203); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32203 designation encode the 17 mm bore and what is 2DD?
last two digits 03 are the ISO bore code, ×5 = 17 mm (codes 00–03 use the 10/12/15/17 exception table). The 40 mm OD and 17.25 mm assembled T follow the ISO 355 dimension-series plan. 2DD is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 32203 list two speeds, 9,900 and 13,000 r/min?
The lower figure, 9,900 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32203 at 13,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32203 mean?
It is the basic open 4T execution — steel cage, adjusted mounting, no seal or feature suffix. NTN uses U for the uprated design, UTG for ULTAGE large-bearing specs, X for the ISO boundary section, and C/CA/D/A for contact-angle or internal-design variants; all are separate order numbers.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.