21322K bearing: complete specifications & equivalents
The 21322K is a ISO 15 radial bearing sized 110 x 240 x 50 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 110 mm |
| Outer diameter D | 240 mm |
| Width B | 50 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 550 kN |
| Basic static load rating C0 | 615 kN |
| Fatigue load limit Pu | 61.5 kN |
| Limiting speed (mechanical) | 1800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 11100 g |
| Manufacturer designation | NTN 21322K |
| 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 & 21300-series range
| Bore d | 4.331 in |
|---|---|
| Outer diameter D | 9.449 in |
| Width B | 1.969 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 65 mm |
| Smallest bore in 21300-series | 40 mm |
| Largest outer diameter in 21300-series | 240 mm |
| Width range across 21300-series | 23–50 mm |
| Bore position in 21300-series (smallest first) | 14 of 14 |
| Bore above smallest 21300-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 21322-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 21300-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 21322-NTN — 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 21322K model number is decoded
21322K is the C design-code execution of NTN's spherical roller range for a 110 mm shaft — 550 kN basic dynamic capacity in a 11100 g, open ISO 15 envelope. Numbering ties 21322K to its envelope and execution: same-number EA versus EM or plain variants share the 110 mm bore but differ in cage and sometimes mass, so they are quoted as separate articles. Suffix reading on 21322K: C is the cage/design code for the NTN 213 series, CK adding the tapered bore; K marks the 1:12 tapered bore; quote the full code because each suffix is a distinct article. Catalogue mass 11100 g (11.10 kg) for the 110×240×50 mm execution includes the C design-code cage and both roller rows; shaft and housing shoulders must support that ring squarely. On vibrating-duty shafts verify the radial clearance class and cage choice at order time; the open 21322K leaves sealing and the C3/C4 clearance decision to the application drawing.
Typical equipment & failure modes
Common applications
- large gearbox and marine gear shafts
- wind-turbine gearbox and rotor bearings
- large vibrating screens and mining feeders
- heavy conveyor and bucket-excavator pulleys
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
- roller-end smearing during skidding starts under light load and high viscosity grease
- brinelling from static overload or a hammer blow during sleeve mounting
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- Mount the 110 mm ring with induction heat or the sleeve drive-up procedure; at 11100 g cocking damages the spherical raceways, and repositioning after seating is impractical.
- Never substitute 21322K by envelope alone: the 615 kN C0 and 61.5 kN Pu are specific to the NTN C design-code execution, and vibrating duty depends heavily on cage identity.
- Do not confuse EA and EM at the same number: 21322K carries C design-code; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 110×240 mm envelope is identical.
- Oil relubrication toward 2,300 r/min needs drain and level design; flooding the 50 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 50 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The 550/615 kN ratings, 61.5 kN Pu and 11100 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 21322K (C design-code); 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 21322K?
21322K is an NTN double-row spherical roller bearing to ISO 15: 110 mm bore, 240 mm OD and 50 mm width (4.331 × 9.449 × 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 550 kN, C0 615 kN, Pu 61.5 kN, grease limiting speed 1,800 r/min, oil 2,300 r/min, mass about 11100 g. It is open, with pressed-steel cage of the 213-series C design and a 1:12 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K denotes a 1:12 tapered bore. 21322K mounts on an adapter sleeve (or tapered shaft seat) and is driven up to the specified residual clearance; its cylindrical-bore counterpart in the same envelope and ratings is 21322.
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. 21322K is the C design-code execution.
What do D1 and W33 mean on 21322K?
21322K 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 21322K take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 21300 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 550 kN C / 615 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.