241-630BK30 bearing: complete specifications & equivalents
The 241-630BK30 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 | 1310000 g |
| Manufacturer designation | NTN 241/630BK30 |
| 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 |
|---|---|---|---|
| 241-630B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24100-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 241-630B — 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 241-630BK30 model number is decoded
241/630BK30 is the basic execution of NTN's spherical roller range for a 630 mm shaft — 12900 kN basic dynamic capacity in a 1310000 g, open ISO 15 envelope. The leading digits are the ISO 15 dimension series (24100 series); the bore code resolves to 630 mm (two-digit code ×5, with the 00–03 exception table), and 1030 mm OD / 400 mm width follow the general plan. The bearing accepts predominantly radial load with a moderate axial share, but is not a pure thrust bearing: sustained axial-only load skids the unloaded row and damages the basic cage. Selection: the C0/C ratio of 1.94 (25000/12900 kN) reflects the heavy static and shock proportioning of 241/630BK30; size the equivalent load at the required L10 with shock factor for the application. 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
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- pressed EA cage fatigue under sustained vibration when minimum load is not maintained
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- false brinelling on stopped machines exposed to screen or crusher vibration
- hard-particle indentation through the open arrangement in dusty mining duty
Selection pitfalls — read before you substitute
- At 630 mm bore 241/630BK30 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 241/630BK30 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The 1:30 tapered bore is the only difference from the cylindrical-bore 241/630B: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- Minimum load must be maintained even at rest under vibration: an unloaded 241/630BK30 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- Never substitute 241/630BK30 by envelope alone: the 25000 kN C0 and 1200 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- The 12900/25000 kN ratings, 1200 kN Pu and 1310000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 241/630BK30 (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 241/630BK30?
241/630BK30 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 1310000 g. It is open, with pressed-steel cage (standard execution) and a 1:30 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K30 denotes a 1:30 tapered bore (the wide 24100 series). 241/630BK30 mounts on a matching adapter or withdrawal sleeve on a plain 630 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 241/630B.
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. 241/630BK30 is the basic execution.
What do D1 and W33 mean on 241/630BK30?
241/630BK30 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 241/630BK30 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.