5208S bearing: complete specifications & equivalents
The 5208S is a ISO 15 radial bearing sized 40 x 80 x 30.2 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 | 80 mm |
| Width B | 30.2 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 44 kN |
| Basic static load rating C0 | 33.5 kN |
| Fatigue load limit Pu | 2 kN |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 620 g |
| Manufacturer designation | NTN 5208S |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 1.189 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 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) | 9 of 18 |
| Bore above smallest 5200S-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 5208S | 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 5208S model number is decoded
NTN 5208S belongs to the medium-duty 5200S double-row family: the catalogue boundary dimensions read 40 / 80 / 30.2 mm (bore / OD / width). The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S 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. NTN prints 44 kN dynamic and 33.5 kN static for this size and a 2 kN fatigue load limit Pu. The 40/80/30.2 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. 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
- 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
- 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
- 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
- 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.
- Do not pair two random 5208S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.
- On a 40 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.
- Never use a four-point or double-row bearing as a like-for-like swap for a single 5208S without re-checking axial float, heat and housing width — the kinematics differ.
- The 44/33.5 kN ratings and 2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5208S; 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 5208S?
5208S is a double-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 30.2 mm width (1.575 x 3.15 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 33.5 kN and a 2 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min; mass about 620 g.
How is the 5208S designation structured?
52 is the double-row dimension series (medium-duty 5200S 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 80 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 5208S support?
5208S 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 5208S?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,100 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 5208S?
The 40/80/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 33.5 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.