5203SCLLM bearing: complete specifications & equivalents
The 5203SCLLM is a ISO 15 radial bearing sized 17 x 40 x 17.5 mm (bore x OD x width) with 2RS 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 | 2RS |
| 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 5203SCLLM |
| 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 |
|---|---|---|---|
| 5203SCLLM | 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 5203SCLLM model number is decoded
The medium-duty 5200S double-row family entry 5203SCLLM carries a 17 mm bore in a 40 mm outside diameter, 17.5 mm wide envelope. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 03 encodes the 17 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. At roughly 11.5 mm of radial section, the catalogue still quotes 12.7 kN dynamic capacity for the 17 mm bore. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 17 mm bore give the working limits.
Typical equipment & failure modes
Common applications
- small machine-tool spindle and live-centre positions
- high-speed router, grinder and woodworking spindles
- small pump and compressor shafts with combined load
- servo and stepper motor shafts with axial preload
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
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
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 LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.
- 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.
- Never use a four-point or double-row bearing as a like-for-like swap for a single 5203SCLLM without re-checking axial float, heat and housing width — the kinematics differ.
- Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.
- The 12.7/8.3 kN ratings and 0.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203SCLLM; 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 5203SCLLM?
5203SCLLM 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 5203SCLLM 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 CLLM marks the SC internal design with non-contact rubber seals 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 5203SCLLM support?
5203SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings.
What lubrication speeds does NTN print for 5203SCLLM?
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 5203SCLLM?
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.