5305S bearing: complete specifications & equivalents
The 5305S is a ISO 15 radial bearing sized 25 x 62 x 25.4 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 25 mm |
| Outer diameter D | 62 mm |
| Width B | 25.4 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 32.5 kN |
| Basic static load rating C0 | 20.7 kN |
| Fatigue load limit Pu | 1.3 kN |
| Limiting speed (mechanical) | 7500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 350 g |
| Manufacturer designation | NTN 5305S |
| 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 & 5300S-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 1 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 18.5 mm |
| Smallest bore in 5300S-series | 15 mm |
| Largest outer diameter in 5300S-series | 150 mm |
| Width range across 5300S-series | 19–63.5 mm |
| Bore position in 5300S-series (smallest first) | 4 of 13 |
| Bore above smallest 5300S-series size | 10 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 5305S model number is decoded
5305S is the 25 mm bore member of NTN's heavy-duty 5300S double-row family, with a 62 mm outside diameter and 25.4 mm section width. Two fields make up the code — 53 is the double-row dimension series (heavy-duty 5300S double-row family) and 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The radial section height here is 18.5 mm, and the catalogue couples that with C 32.5 kN / C0 20.7 kN. The 25/62/25.4 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. 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
- small pump and compressor shafts with combined load
- servo and stepper motor shafts with axial preload
- bicycle and motorcycle wheel and steering positions
- small gearbox pinion shafts with helical gears
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
- loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow
- resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
- contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue
Selection pitfalls — read before you substitute
- At 25 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.
- The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.
- 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.
- On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.
- A single-row angular contact left loose on the shaft to "help assembly" will fret the seat: the contact angle keeps driving the ring axially under load.
- The 32.5/20.7 kN ratings and 1.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5305S; 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 5305S?
5305S is a double-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 25.4 mm width (0.984 x 2.441 x 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 32.5 kN, C0 20.7 kN and a 1.3 kN fatigue load limit Pu; the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min; mass about 350 g.
How is the 5305S designation structured?
53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 62 mm OD and 25.4 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 5305S support?
5305S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope.
What lubrication speeds does NTN print for 5305S?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,500 r/min and the oil rating 10,000 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 5305S?
The 25/62/25.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 32.5 kN / C0 20.7 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.