241-670B bearing: complete specifications & equivalents
The 241-670B is a ISO 15 radial bearing sized 670 x 1090 x 412 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 670 mm |
| Outer diameter D | 1090 mm |
| Width B | 412 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 14100 kN |
| Basic static load rating C0 | 28000 kN |
| Fatigue load limit Pu | 1340 kN |
| Limiting speed (mechanical) | 230 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1530000 g |
| Manufacturer designation | NTN 241/670B |
| 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 | 26.378 in |
|---|---|
| Outer diameter D | 42.913 in |
| Width B | 16.22 in |
| ISO bore code | 41 |
| Radial section height (D−d)/2 | 210 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) | 31 of 32 |
| Bore above smallest 24100-series size | 570 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 241-670BK30 | 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 241-670BK30 (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 241-670B model number is decoded
NTN lists 241/670B with a cylindrical bore and plain outer ring (no D1/W33 groove): 670 mm bore, 1090 mm OD, 412 mm width, rated 230 r/min on grease. On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (cylindrical), lubrication feature (none); 241/670B is assembled exactly in that order. Two symmetric roller rows share the load: C 14100 kN, C0 28000 kN (C0/C ≈ 1.99), with useful axial capacity in either direction alongside the dominant radial load. Selection: the C0/C ratio of 1.99 (28000/14100 kN) reflects the heavy static and shock proportioning of 241/670B; size the equivalent load at the required L10 with shock factor for the application. After mounting on a tapered seat, lock the nut and re-check clearance after a short running-in period, because sleeve seating and ring lift-off can change the residual clearance of the 670 mm set.
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
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- 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
- rolling-contact fatigue after the catalogue L10 life at the actual load
- hard-particle indentation through the open arrangement in dusty mining duty
Selection pitfalls — read before you substitute
- At 670 mm bore 241/670B 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.
- Never substitute 241/670B by envelope alone: the 28000 kN C0 and 1340 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- The cylindrical-bore 241/670B and its tapered-bore counterpart 241/670BK30 share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- Never substitute 241/670B by envelope alone: the 28000 kN C0 and 1340 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 670 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- The 14100/28000 kN ratings, 1340 kN Pu and 1530000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 241/670B (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 241/670B?
241/670B is an NTN double-row spherical roller bearing to ISO 15: 670 mm bore, 1090 mm OD and 412 mm width (26.378 × 42.913 × 16.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14100 kN, C0 28000 kN, Pu 1340 kN, grease limiting speed 230 r/min, oil 300 r/min, mass about 1530000 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?
241/670B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 241/670BK30 (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. 241/670B is the basic execution.
What do D1 and W33 mean on 241/670B?
241/670B 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 241/670B 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 — 14100 kN C / 28000 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.