239-630K bearing: complete specifications & equivalents
The 239-630K is a ISO 15 radial bearing sized 630 x 850 x 165 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 630 mm |
| Outer diameter D | 850 mm |
| Width B | 165 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 4100 kN |
| Basic static load rating C0 | 9250 kN |
| Fatigue load limit Pu | 545 kN |
| Limiting speed (mechanical) | 320 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 268000 g |
| Manufacturer designation | NTN 239/630K |
| 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 & 23900-series range
| Bore d | 24.803 in |
|---|---|
| Outer diameter D | 33.465 in |
| Width B | 6.496 in |
| ISO bore code | 39 |
| Radial section height (D−d)/2 | 110 mm |
| Smallest bore in 23900-series | 160 mm |
| Largest outer diameter in 23900-series | 1820 mm |
| Width range across 23900-series | 45–315 mm |
| Bore position in 23900-series (smallest first) | 24 of 38 |
| Bore above smallest 23900-series size | 470 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 239-630 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 239-630 — mounting (adapter/withdrawal sleeve or tapered seat, drive-up) differs. Verify shaft arrangement. |
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 239-630K model number is decoded
239/630K is the basic execution of NTN's spherical roller range for a 630 mm shaft — 4100 kN basic dynamic capacity in a 268000 g, open ISO 15 envelope. Digit by digit the code reads as spherical-roller dimension series plus 630 mm bore; the 165 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. NTN prints two speeds for 239/630K: 320 r/min grease and 420 r/min oil — the gap of 100 r/min reflects oil cooling of the heavy roller set. The 110.0 mm section height hosts the spherical roller geometry; shaft and housing fillet radii must clear the chamfer table so the 165 mm-wide ring seats fully on both sides. On vibrating-duty shafts verify the radial clearance class and cage choice at order time; the open 239/630K leaves sealing and the C3/C4 clearance decision to the application drawing.
Typical equipment & failure modes
Common applications
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
Known failure patterns
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- brinelling from static overload or a hammer blow during sleeve mounting
- rolling-contact fatigue after the catalogue L10 life at the actual load
Selection pitfalls — read before you substitute
- At 630 mm bore 239/630K is normally mounted on adapter/withdrawal sleeves with hydraulic assistance; follow the NTN drive-up angle or oil-injection procedure — manual nut tightening cannot set the multi-tonne seating correctly.
- Oil relubrication toward 420 r/min needs drain and level design; flooding the 165 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 630 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- The 1:12 tapered bore is the only difference from the cylindrical-bore 239/630: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- Oil relubrication toward 420 r/min needs drain and level design; flooding the 165 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 4100/9250 kN ratings, 545 kN Pu and 268000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 239/630K (basic); another maker's same-envelope part revises internal geometry, so re-verify ratings and cage before substitution on vibrating or rated drives.
Frequently asked questions
What are the dimensions and catalogue data of 239/630K?
239/630K is an NTN double-row spherical roller bearing to ISO 15: 630 mm bore, 850 mm OD and 165 mm width (24.803 × 33.465 × 6.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 4100 kN, C0 9250 kN, Pu 545 kN, grease limiting speed 320 r/min, oil 420 r/min, mass about 268000 g. It is open, with pressed-steel cage (standard execution) and a 1:12 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K denotes a 1:12 tapered bore. 239/630K mounts on an adapter sleeve (or tapered shaft seat) and is driven up to the specified residual clearance; its cylindrical-bore counterpart in the same envelope and ratings is 239/630.
What do EA and EM mean on NTN spherical roller bearings?
EA is the NTN standard-capacity/high-capacity execution with a pressed sheet-steel window cage; EM is the high-capacity execution with a one-piece machined brass cage. Both use the optimised symmetric-roller design, but cage identity changes mass, speed behaviour and suitability for duties like vibrating screens, so they are separate order numbers. 239/630K is the basic execution.
What do D1 and W33 mean on 239/630K?
239/630K is listed without a D1/W33 outer-ring groove in 2203E; lubrication is supplied from the ring sides. D1 (NTN spelling) and W33 add the annular groove plus holes and are ordered as distinct suffixed executions of the same envelope.
How much misalignment and axial load can 239/630K take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23900 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 4100 kN C / 9250 kN C0 — but sustained pure axial load is not recommended because it unloads one row.
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.