5203SCZZ bearing: complete specifications & equivalents
The 5203SCZZ is a ISO 15 radial bearing sized 17 x 40 x 17.5 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 | 17.5 mm |
| Material | GCr15 |
| Seal / shield | ZZ |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 12.7 kN |
| Basic static load rating C0 | 8.3 kN |
| Fatigue load limit Pu | 0.49 kN |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 100 g |
| Manufacturer designation | NTN 5203SCZZ |
| Standard | ISO 15 |
| 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 & 5200S-series range
| Bore d | 0.669 in |
|---|---|
| Outer diameter D | 1.575 in |
| Width B | 0.689 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 11.5 mm |
| Smallest bore in 5200S-series | 10 mm |
| Largest outer diameter in 5200S-series | 150 mm |
| Width range across 5200S-series | 14.3–49.2 mm |
| Bore position in 5200S-series (smallest first) | 4 of 18 |
| Bore above smallest 5200S-series size | 7 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 5203SCZZ | 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. |
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 5203SCZZ model number is decoded
5203SCZZ is an NTN sealed double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 17 x 40 x 17.5 mm. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. Catalogue mass is about 100 g, which at this 11.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one.
Typical equipment & failure modes
Common applications
- high-speed router, grinder and woodworking spindles
- small pump and compressor shafts with combined load
- servo and stepper motor shafts with axial preload
- bicycle and motorcycle wheel and steering positions
Known failure patterns
- impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface
- lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated
- lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated
Selection pitfalls — read before you substitute
- At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.
- Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.
- Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.
- The C0 of 8.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.
- If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.
- The 12.7/8.3 kN ratings and 0.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 5203SCZZ?
5203SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 17.5 mm width (0.669 x 1.575 x 0.689 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.7 kN, C0 8.3 kN and a 0.49 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 100 g.
How is the 5203SCZZ designation structured?
52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 40 mm OD and 17.5 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 5203SCZZ support?
5203SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings.
What lubrication speeds does NTN print for 5203SCZZ?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit.
What should be checked before substituting another make for 5203SCZZ?
The 17/40/17.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.7 kN / C0 8.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive.
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.