240-800B bearing: complete specifications & equivalents
The 240-800B is a ISO 15 radial bearing sized 800 x 1150 x 345 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 800 mm |
| Outer diameter D | 1150 mm |
| Width B | 345 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 12400 kN |
| Basic static load rating C0 | 27800 kN |
| Fatigue load limit Pu | 1360 kN |
| Limiting speed (mechanical) | 200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1190000 g |
| Manufacturer designation | NTN 240/800B |
| 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 & 24000-series range
| Bore d | 31.496 in |
|---|---|
| Outer diameter D | 45.276 in |
| Width B | 13.583 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 175 mm |
| Smallest bore in 24000-series | 65 mm |
| Largest outer diameter in 24000-series | 1580 mm |
| Width range across 24000-series | 35–462 mm |
| Bore position in 24000-series (smallest first) | 36 of 42 |
| Bore above smallest 24000-series size | 735 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 240-800BK30 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 240-800BK30 (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 240-800B model number is decoded
240/800B is the basic execution of NTN's spherical roller range for a 800 mm shaft — 12400 kN basic dynamic capacity in a 1190000 g, open ISO 15 envelope. Reading the full code: the number gives the 800×1150 mm envelope, — names the cage/capacity execution, no bore suffix means cylindrical bore for a direct shaft seat, and plain outer ring (no D1/W33 groove) completes the order number. Suffix reading on 240/800B: the bare number is the standard open execution; B marks the standard large-bore internal design on slash-size 230–232 series; quote the full code because each suffix is a distinct article. With about 15.5 kN of C per millimetre of the 800 mm bore, 240/800B screens interchange candidates quickly — then verify cage (EA/EM), bore (K/K30) and lubrication feature (D1/W33) suffixes. Never mount 240/800B by striking the outer ring through the roller set; drive through ring faces (or the adapter sleeve nut) and support the ring square to avoid brinelling the 1150 mm race.
Typical equipment & failure modes
Common applications
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
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
- roller-end smearing during skidding starts under light load and high viscosity grease
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 800 mm bore 240/800B 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.
- Do not confuse EA and EM at the same number: 240/800B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 800×1150 mm envelope is identical.
- Minimum load must be maintained even at rest under vibration: an unloaded 240/800B on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 345 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 345 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The 12400/27800 kN ratings, 1360 kN Pu and 1190000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/800B (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 240/800B?
240/800B is an NTN double-row spherical roller bearing to ISO 15: 800 mm bore, 1150 mm OD and 345 mm width (31.496 × 45.276 × 13.583 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12400 kN, C0 27800 kN, Pu 1360 kN, grease limiting speed 200 r/min, oil 260 r/min, mass about 1190000 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?
240/800B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 240/800BK30 (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. 240/800B is the basic execution.
What do D1 and W33 mean on 240/800B?
240/800B 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 240/800B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 12400 kN C / 27800 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.