241-630B bearing: complete specifications & equivalents
The 241-630B is a ISO 15 radial bearing sized 630 x 1030 x 400 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 | 1030 mm |
| Width B | 400 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 12900 kN |
| Basic static load rating C0 | 25000 kN |
| Fatigue load limit Pu | 1200 kN |
| Limiting speed (mechanical) | 250 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1330000 g |
| Manufacturer designation | NTN 241/630B |
| 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 & 24100-series range
| Bore d | 24.803 in |
|---|---|
| Outer diameter D | 40.551 in |
| Width B | 15.748 in |
| ISO bore code | 41 |
| Radial section height (D−d)/2 | 200 mm |
| Smallest bore in 24100-series | 100 mm |
| Largest outer diameter in 24100-series | 1150 mm |
| Width range across 24100-series | 65–438 mm |
| Bore position in 24100-series (smallest first) | 30 of 32 |
| Bore above smallest 24100-series size | 530 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 241-630BK30 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24100-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 241-630BK30 (K/K30 sleeve or tapered-seat mounting). 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 241-630B model number is decoded
241/630B belongs to the 24100 series of NTN spherical rollers: self-aligning, high radial capacity, moderate axial load in either direction. Digit by digit the code reads as spherical-roller dimension series plus 630 mm bore; the 400 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. The sphered outer raceway lets the inner-ring assembly pivot, accommodating shaft deflection and housing misalignment (around 1–2° for this class; use the 2203E value for the exact series) without edge loading the rollers. Grease/oil ratio: the 250 r/min limiting value is .78 of the 320 r/min oil value; heavy 400 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Fillet radii on shaft and housing must clear the ring chamfers of the 400 mm-wide set; use the NTN shoulder/withdrawal-groove table rather than copying a ball-bearing layout.
Typical equipment & failure modes
Common applications
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- cage damage when a mounting force is applied through the roller set instead of the ring face
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 630 mm bore 241/630B 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.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 241/630B in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- K and K30 are different tapers — K is 1:12 and K30 is 1:30 on the wide series; an adapter sleeve for one will not mount the other 630 mm bearing, and drive-up procedures differ.
- Oil relubrication toward 320 r/min needs drain and level design; flooding the 400 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Minimum load must be maintained even at rest under vibration: an unloaded 241/630B on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The 12900/25000 kN ratings, 1200 kN Pu and 1330000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 241/630B (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 241/630B?
241/630B is an NTN double-row spherical roller bearing to ISO 15: 630 mm bore, 1030 mm OD and 400 mm width (24.803 × 40.551 × 15.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12900 kN, C0 25000 kN, Pu 1200 kN, grease limiting speed 250 r/min, oil 320 r/min, mass about 1330000 g. It is open, with pressed-steel cage (standard execution).
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
241/630B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 241/630BK30 (K = 1:12, or K30 = 1:30 on the wide series), intended for adapter/withdrawal-sleeve mounting.
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. 241/630B is the basic execution.
What do D1 and W33 mean on 241/630B?
241/630B 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 241/630B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24100 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 12900 kN C / 25000 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.