21314-EK bearing: complete specifications & equivalents
The 21314-EK 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 | SKF |
| 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 | 291 kN |
| Basic static load rating C0 | 325 kN |
| Fatigue load limit Pu | 34.5 kN |
| Reference speed (thermal) | 4000 rpm |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3700 g |
| Manufacturer designation | SKF 21314 EK |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.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 | 14 |
| 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 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 21314 | SKF | full Dimensions and internal design equivalent — standard interchange. | Tapered-bore (1:12) sleeve-mounted execution of 21314; identical ISO 15 envelope, fits H314 adapter sleeve on a 60 mm shaft. |
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 21314-EK model number is decoded
In SKF catalogue PUB BU/P1 17000, 21314-ek denotes the tapered-bore version (K suffix, taper 1:12) of the 21300-series spherical roller bearing: dimensioned 70×150×35 mm, it seats on an adapter or withdrawal sleeve rather than directly on a machined journal. The code breaks down as type digit 2 (double-row spherical roller), dimension series 13 (dimension series 13 (heavy OD, normal width)), and bore code 14 = 70 mm; dimensions 70×150×35 mm therefore match the ISO 15 envelope. Sleeve mounting is why the K execution exists: a plain h9-tolerance shaft is enough because the adapter sleeve supplies the precision seat, and the bearing is removable without pulling over an interference journal — a separate order number from the cylindrical-bore bearing, never a field conversion. The 34.5 kN Pu figure feeds the adjusted-life equation at contaminated or partial-film conditions, and the 1.12 C0/C balance shows this execution is tuned to heavy radial-plus-axial duty with misalignment tolerance. Mounting on the 1:12 taper is controlled by clearance reduction or measured axial drive-up, never by locknut torque: SKF tables give the target radial-clearance decrease for the 70 mm 21314-ek, checked with feeler gauges before and after drive-up.
Typical equipment & failure modes
Common applications
- cement-mill trunnion and drive shafts
- heavy conveyor head shafts in mining
- split-housing plummer block arrangements with bearings swapped in situ
- heavy crusher and screen shafts mounted and dismounted with hydraulic nuts
Known failure patterns
- raceway fatigue spalling of the sphered outer raceway after extended service above the catalogue L10 rating
- inner-ring raceway spalling from edge loading when misalignment exceeds the self-aligning recovery range
- sleeve seizure and shaft seat damage from omitting the anti-seize film between withdrawal sleeve and journal before drive-up
- surface distress and smearing when the relubrication interval is exceeded — the W33 groove is only effective if grease actually reaches the roller rows
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- Mount the 70 mm bore 21314-ek by induction heating (max 120 °C) or oil injection — driving a bearing of this section home through the rollers brinells both raceways, and the damage only speaks up as vibration hours later.
- The 21300-series series at 70 mm bore (150×35 mm) pairs a heavy OD with a narrow section — a compact way to add capacity, but the shoulder and abutment diameters differ from the 222 series; it is not a drop-in swap.
- The 21314-ek and its cylindrical-bore counterpart 21314 share envelope and load ratings (291/325 kN) but are not interchangeable in a housing already fitted for direct shaft mounting — the sleeve changes the assembly stack-up.
- The adapter sleeve is selected by actual shaft diameter, not by the 70 mm nominal bearing bore: H-sleeve part numbers span a small diameter range, so two different shaft diameters can use the same 21314-ek with different sleeves.
- The self-aligning feature is not a license to ignore alignment: beyond ≈ 0.5–2.5° (series-dependent) the edge loading eats the fatigue margin, and seal drag grows as the rings tilt.
- The 291/325 kN ratings are SKF catalogue values for this tapered-bore execution (SKF 21314 EK); sleeve, KM nut and MB washer are separate order numbers, and the catalogue version (SKF catalogue PUB BU/P1 17000) should travel with the mounting specification.
Frequently asked questions
What are the dimensions and catalogue data of 21314-ek?
The SKF 21314 EK is a double-row spherical roller bearing with a 1:12 tapered bore, 70 mm nominal bore, 150 mm outer diameter and 35 mm width (2.756 × 5.906 × 1.378 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: C 291 kN, C0 325 kN, Pu 34.5 kN, reference speed 4,000 r/min, limiting speed 5,600 r/min, mass about 3700 g. It is mounted on an adapter (H) or withdrawal (AH) sleeve, not directly on the shaft.
What does the K suffix mean on 21314-ek?
K marks a 1:12 tapered bore for sleeve mounting — SKF writes EK or CCK(/W33), FAG writes -K- inside the suffix chain for sleeve mounting. The bearing seats on an H-series adapter sleeve with a KM locknut and MB lock washer (plain shaft, h9 tolerance), or on an AH withdrawal sleeve against a shaft shoulder. The rarer K30 suffix would instead mean a 1:30 taper; dimension series 40/41 spherical rollers commonly use it.
Which adapter sleeve fits the 21314-ek?
The sleeve is selected by the actual shaft diameter in millimetres, not only by the 70 mm nominal bore: SKF H-sleeve numbers each cover a small shaft-diameter range and are width-series specific (H39/H30/H31/H32 matching dimension series 39/40/31/32), and each kit bundles the sleeve, KM locknut and MB lock washer. For shoulder locations use an AH withdrawal sleeve instead. Confirm the sleeve number against the SKF catalogue PUB BU/P1 17000 mounting tables for your shaft size.
How is the 21314-ek driven up and checked?
Mounting is controlled by radial-clearance reduction or axial drive-up distance from the SKF catalogue tables for the 1:12 taper, never by locknut torque. Measure clearance with feeler gauges before and after tightening the KM nut, stop at the tabulated decrease, and lock the MB washer tab. Over-drive removes too much clearance (inner-ring cracking risk); under-drive lets the sleeve creep and fret.
What is the difference between 21314-ek and 21314?
They share the ISO 15 envelope and the same 291/325 kN ratings, but 21314-ek has the 1:12 tapered bore for sleeve mounting on a plain shaft, while 21314 has a cylindrical bore for direct mounting on a machined interference journal (typically k5 with H7 housing). They are separate order numbers, not interchangeable in the same shaft arrangement.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions on 2026-09-26. Read our editorial & correction policy.