21314K bearing: complete specifications & equivalents
The 21314K is a ISO 15 radial bearing sized 70 x 150 x 35 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 70 mm |
| Outer diameter D | 150 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 245 kN |
| Basic static load rating C0 | 262 kN |
| Fatigue load limit Pu | 33.5 kN |
| Limiting speed (mechanical) | 2900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3140 g |
| Manufacturer designation | NTN 21314K |
| 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 | 2.756 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.378 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 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) | 7 of 14 |
| Bore above smallest 21300-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 21314-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 21314-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 21314K model number is decoded
The NTN order number 21314K identifies a 70×150×35 mm (2.756 × 5.906 × 1.378 in) spherical roller bearing, 1:12 tapered bore (K), to the ISO 15 boundary plan. The leading digits are the ISO 15 dimension series (21300 series); the bore code resolves to 70 mm (two-digit code ×5, with the 00–03 exception table), and 150 mm OD / 35 mm width follow the general plan. NTN prints two speeds for 21314K: 2,900 r/min grease and 3,800 r/min oil — the gap of 900 r/min reflects oil cooling of the heavy roller set. Catalogue mass 3140 g (3.14 kg) for the 70×150×35 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 21314K leaves sealing and the C3/C4 clearance decision to the application drawing.
Typical equipment & failure modes
Common applications
- jaw/cone crusher eccentric and shaft positions
- paper-machine dryer and press rolls
- cement-mill and kiln auxiliary drives
- large gearbox and marine gear shafts
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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
- rolling-contact fatigue after the catalogue L10 life at the actual load
Selection pitfalls — read before you substitute
- Mount the 70 mm ring with induction heat or the sleeve drive-up procedure; at 3140 g cocking damages the spherical raceways, and repositioning after seating is impractical.
- Never substitute 21314K by envelope alone: the 262 kN C0 and 33.5 kN Pu are specific to the NTN C design-code execution, and vibrating duty depends heavily on cage identity.
- 213-series C/CK executions use the C cage/design code — CK adds the 1:12 tapered bore; quote 21314K in full because a C cannot be mounted on an adapter-sleeve tapered seat.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 35 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- Oil relubrication toward 3,800 r/min needs drain and level design; flooding the 35 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 245/262 kN ratings, 33.5 kN Pu and 3140 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 21314K (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 21314K?
21314K is an NTN double-row spherical roller bearing to ISO 15: 70 mm bore, 150 mm OD and 35 mm width (2.756 × 5.906 × 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 245 kN, C0 262 kN, Pu 33.5 kN, grease limiting speed 2,900 r/min, oil 3,800 r/min, mass about 3140 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. 21314K 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 21314.
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. 21314K is the C design-code execution.
What do D1 and W33 mean on 21314K?
21314K 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 21314K 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 — 245 kN C / 262 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.