21313-NTN bearing: complete specifications & equivalents
The 21313-NTN is a ISO 15 radial bearing sized 65 x 140 x 33 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 65 mm |
| Outer diameter D | 140 mm |
| Width B | 33 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 216 kN |
| Basic static load rating C0 | 228 kN |
| Fatigue load limit Pu | 31 kN |
| Limiting speed (mechanical) | 3100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2550 g |
| Manufacturer designation | NTN 21313 |
| 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 | 2.559 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 1.299 in |
| ISO bore code | 13 |
| Radial section height (D−d)/2 | 37.5 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) | 6 of 14 |
| Bore above smallest 21300-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 21313K | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 21300-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 21313K (K/K30 sleeve or tapered-seat mounting). Verify shaft arrangement. |
| 21313 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 21313-EK | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 21313-NTN model number is decoded
For heavy radial load with misalignment on a 65 mm shaft, NTN supplies 21313: sphered outer raceway, two roller rows, pressed-steel cage of the 213-series C design, oil speed 4,000 r/min. Digit by digit the code reads as spherical-roller dimension series plus 65 mm bore; the 33 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. Open by design, 21313 requires application seals and a grease or oil system; NTN vibrating-duty executions of this envelope are selected with cage and clearance choices that are separate order codes. Grease/oil ratio: the 3,100 r/min limiting value is .78 of the 4,000 r/min oil value; heavy 33 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Never mount 21313 by striking the outer ring through the roller set; drive through ring faces (or the adapter sleeve nut) and support the ring square to avoid brinelling the 140 mm race.
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
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- 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
- rolling-contact fatigue after the catalogue L10 life at the actual load
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- Mount the 65 mm ring with induction heat or the sleeve drive-up procedure; at 2550 g cocking damages the spherical raceways, and repositioning after seating is impractical.
- 213-series C/CK executions use the C cage/design code — CK adds the 1:12 tapered bore; quote 21313 in full because a C cannot be mounted on an adapter-sleeve tapered seat.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 65 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K seats.
- Oil relubrication toward 4,000 r/min needs drain and level design; flooding the 33 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 216 kN rating no longer applies.
- The 216/228 kN ratings, 31 kN Pu and 2550 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 21313 (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 21313?
21313 is an NTN double-row spherical roller bearing to ISO 15: 65 mm bore, 140 mm OD and 33 mm width (2.559 × 5.512 × 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 216 kN, C0 228 kN, Pu 31 kN, grease limiting speed 3,100 r/min, oil 4,000 r/min, mass about 2550 g. It is open, with pressed-steel cage of the 213-series C design.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
21313 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 21313K (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. 21313 is the C design-code execution.
What do D1 and W33 mean on 21313?
21313 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 21313 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 — 216 kN C / 228 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.