5308S bearing: complete specifications & equivalents
The 5308S is a ISO 15 radial bearing sized 40 x 90 x 36.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 90 mm |
| Width B | 36.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 56.5 kN |
| Basic static load rating C0 | 41 kN |
| Fatigue load limit Pu | 2.5 kN |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1030 g |
| Manufacturer designation | NTN 5308S |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 1.437 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 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) | 7 of 13 |
| Bore above smallest 5300S-series size | 25 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 5308S model number is decoded
5308S is an NTN double-row angular contact ball bearing: heavy-duty 5300S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 40 x 90 x 36.5 mm. Decoding 5308S: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue dynamic rating C is 56.5 kN against C0 41 kN — a C0/C ratio of 0.73 that is typical of an angular-contact contact ellipse. Choose the heavy-duty 5300S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 40 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it.
Typical equipment & failure modes
Common applications
- agricultural gearbox and PTO shaft supports
- printing-press cylinder and folder shafts
- machine-tool spindle cartridges and driven tooling
- industrial pump and blower impeller shafts
Known failure patterns
- false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch
- thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear
- resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer
- flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share
- current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways
Selection pitfalls — read before you substitute
- In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.
- 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.
- A 5308S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.
- A 5308S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.
- 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 56.5/41 kN ratings and 2.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5308S; 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 5308S?
5308S is a double-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 36.5 mm width (1.575 x 3.543 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 56.5 kN, C0 41 kN and a 2.5 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min; mass about 1030 g.
How is the 5308S designation structured?
53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 90 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 5308S support?
5308S 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 5308S?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and the oil rating 6,700 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 5308S?
The 40/90/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 56.5 kN / C0 41 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.