230-630B bearing: complete specifications & equivalents
The 230-630B is a ISO 15 radial bearing sized 630 x 920 x 212 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 | 920 mm |
| Width B | 212 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 6550 kN |
| Basic static load rating C0 | 13000 kN |
| Fatigue load limit Pu | 950 kN |
| Limiting speed (mechanical) | 310 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 481000 g |
| Manufacturer designation | NTN 230/630B |
| 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 & 23000-series range
| Bore d | 24.803 in |
|---|---|
| Outer diameter D | 36.22 in |
| Width B | 8.346 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 145 mm |
| Smallest bore in 23000-series | 70 mm |
| Largest outer diameter in 23000-series | 1580 mm |
| Width range across 23000-series | 27–345 mm |
| Bore position in 23000-series (smallest first) | 36 of 46 |
| Bore above smallest 23000-series size | 560 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 230-630BK | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 230-630BK (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 230-630B model number is decoded
230/630B is an NTN double-row spherical roller bearing: two rows of symmetric rollers on a sphered outer raceway, 630×920×212 mm to ISO 15, with pressed-steel cage (standard execution). Reading the full code: the number gives the 630×920 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. At 6550 kN C and 481000 g mass the 23000 series part is built for shock and vibration; the 212 mm-wide ring needs square abutments to keep both rows equally loaded. Grease/oil ratio: the 310 r/min limiting value is .78 of the 400 r/min oil value; heavy 212 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. On vibrating-duty shafts verify the radial clearance class and cage choice at order time; the open 230/630B leaves sealing and the C3/C4 clearance decision to the application drawing.
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
- 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
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
- hard-particle indentation through the open arrangement in dusty mining duty
Selection pitfalls — read before you substitute
- At 630 mm bore 230/630B 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 two roller rows must share load equally — a tilted spacer or unequal abutment on the 212 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 230/630B in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 6550 kN rating no longer applies.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 310 r/min grease rating is lost to abrasive wear long before fatigue.
- The 6550/13000 kN ratings, 950 kN Pu and 481000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 230/630B (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 230/630B?
230/630B is an NTN double-row spherical roller bearing to ISO 15: 630 mm bore, 920 mm OD and 212 mm width (24.803 × 36.22 × 8.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 6550 kN, C0 13000 kN, Pu 950 kN, grease limiting speed 310 r/min, oil 400 r/min, mass about 481000 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?
230/630B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 230/630BK (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. 230/630B is the basic execution.
What do D1 and W33 mean on 230/630B?
230/630B 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 230/630B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 6550 kN C / 13000 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.