21316-NTN bearing: complete specifications & equivalents
The 21316-NTN is a ISO 15 radial bearing sized 80 x 170 x 39 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 80 mm |
| Outer diameter D | 170 mm |
| Width B | 39 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 289 kN |
| Basic static load rating C0 | 315 kN |
| Fatigue load limit Pu | 30.5 kN |
| Limiting speed (mechanical) | 2500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 4530 g |
| Manufacturer designation | NTN 21316 |
| 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 | 3.15 in |
|---|---|
| Outer diameter D | 6.693 in |
| Width B | 1.535 in |
| ISO bore code | 16 |
| Radial section height (D−d)/2 | 45 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) | 9 of 14 |
| Bore above smallest 21300-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 21316K | 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 21316K (K/K30 sleeve or tapered-seat mounting). Verify shaft arrangement. |
| 21316 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 21316-EK | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 80×170×39 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 21316-NTN model number is decoded
The NTN order number 21316 identifies a 80×170×39 mm (3.15 × 6.693 × 1.535 in) spherical roller bearing, cylindrical bore, to the ISO 15 boundary plan. Numbering ties 21316 to its envelope and execution: same-number EA versus EM or plain variants share the 80 mm bore but differ in cage and sometimes mass, so they are quoted as separate articles. NTN prints two speeds for 21316: 2,500 r/min grease and 3,300 r/min oil — the gap of 800 r/min reflects oil cooling of the heavy roller set. Catalogue mass 4530 g (4.53 kg) for the 80×170×39 mm execution includes the C design-code cage and both roller rows; shaft and housing shoulders must support that ring squarely. Fillet radii on shaft and housing must clear the ring chamfers of the 39 mm-wide set; use the NTN shoulder/withdrawal-groove table rather than copying a ball-bearing layout.
Typical equipment & failure modes
Common applications
- heavy conveyor and bucket-excavator pulleys
- jaw/cone crusher eccentric and shaft positions
- paper-machine dryer and press rolls
- cement-mill and kiln auxiliary drives
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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- water-induced pitting in washdown or outdoor duty without effective external seals
- hard-particle indentation through the open arrangement in dusty mining duty
Selection pitfalls — read before you substitute
- Mount the 80 mm ring with induction heat or the sleeve drive-up procedure; at 4530 g cocking damages the spherical raceways, and repositioning after seating is impractical.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 289 kN rating no longer applies.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 21316 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Do not confuse EA and EM at the same number: 21316 carries C design-code; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 80×170 mm envelope is identical.
- Oil relubrication toward 3,300 r/min needs drain and level design; flooding the 39 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 289/315 kN ratings, 30.5 kN Pu and 4530 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 21316 (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 21316?
21316 is an NTN double-row spherical roller bearing to ISO 15: 80 mm bore, 170 mm OD and 39 mm width (3.15 × 6.693 × 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 289 kN, C0 315 kN, Pu 30.5 kN, grease limiting speed 2,500 r/min, oil 3,300 r/min, mass about 4530 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?
21316 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 21316K (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. 21316 is the C design-code execution.
What do D1 and W33 mean on 21316?
21316 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 21316 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 — 289 kN C / 315 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.