240-800BK30 bearing: complete specifications & equivalents
The 240-800BK30 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 | 1170000 g |
| Manufacturer designation | NTN 240/800BK30 |
| 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 |
|---|---|---|---|
| 240-800B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 240-800B — 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 240-800BK30 model number is decoded
240/800BK30 is the basic execution of NTN's spherical roller range for a 800 mm shaft — 12400 kN basic dynamic capacity in a 1170000 g, open ISO 15 envelope. On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (K30), lubrication feature (none); 240/800BK30 is assembled exactly in that order. The 175.0 mm radial section over the 800 mm bore carries two roller rows; capacity per millimetre of bore is about 15.5 kN/mm, among the highest of rolling bearings for the ISO 15 envelope. With about 15.5 kN of C per millimetre of the 800 mm bore, 240/800BK30 screens interchange candidates quickly — then verify cage (EA/EM), bore (K/K30) and lubrication feature (D1/W33) suffixes. Supply grease through the outer-ring feature during commissioning and at the calculated interval, rotating the 800 mm bore assembly by hand to distribute it across both rows.
Typical equipment & failure modes
Common applications
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
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
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
- brinelling from static overload or a hammer blow during sleeve mounting
Selection pitfalls — read before you substitute
- At 800 mm bore 240/800BK30 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 240/800BK30 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Do not confuse EA and EM at the same number: 240/800BK30 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.
- 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 1:30 tapered bore is the only difference from the cylindrical-bore 240/800B: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- The 12400/27800 kN ratings, 1360 kN Pu and 1170000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/800BK30 (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 240/800BK30?
240/800BK30 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 1170000 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 24000 series). 240/800BK30 mounts on a matching adapter or withdrawal sleeve on a plain 800 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 240/800B.
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. 240/800BK30 is the basic execution.
What do D1 and W33 mean on 240/800BK30?
240/800BK30 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 240/800BK30 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.