NU316 bearing: complete specifications & equivalents
The NU316 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 | SKF |
| 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 | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 300 kN |
| Basic static load rating C0 | 290 kN |
| Fatigue load limit Pu | 36 kN |
| Reference speed (thermal) | 4300 rpm |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3850 g |
| Manufacturer designation | NU 316 ECP |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings); 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 & NU300-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 NU300-series | 17 mm |
| Largest outer diameter in NU300-series | 620 mm |
| Width range across NU300-series | 14–109 mm |
| Bore position in NU300-series (smallest first) | 14 of 34 |
| Bore above smallest NU300-series size | 63 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU316-NTN | NTN | 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. |
| 6316 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6316-2RS | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6316-ZZ | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| N316-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 316 ECP is a different execution with its own cage/flange configuration. |
| NJ316-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 316 ECP is a different execution with its own cage/flange configuration. |
| NUP316-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 316 ECP is a different execution with its own cage/flange configuration. |
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 NU316 model number is decoded
SKF NU316 (NU 316 ECP) is the standard cylindrical roller choice for a 80 mm shaft — one row of precisely profiled rollers on ground raceways inside the 170×39 mm ISO 15 envelope. Numbering ties the bearing to its envelope: NU316 means cylindrical-roller type NU, standard series 3, 80 mm bore — which is why the 170×39 mm outline swaps dimensionally with other ISO 15 bearings of the same code. The SKF catalogue adds the ECP suffix for the standard glass-fibre reinforced polyamide cage; ECJ (pressed steel) and ECM (machined brass) are alternative executions with different speed and temperature ratings. Selection arithmetic: the C0/C ratio is about 0.97 (static 290 kN against dynamic 300 kN), typical of a cylindrical roller sized for high radial capacity, and the 36 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. The outer ring has no ribs and cannot locate the shaft axially; pair NU316 with a locating bearing (e.g. deep-groove ball or angular contact) or use an NJ/NUP variant if one-direction location is required.
Typical equipment & failure modes
Common applications
- heavy industrial gearbox shafts
- large pump and turbine shafts
- rolling-mill work-roll backup bearings
- paper-machine dryer and calender rolls
Known failure patterns
- inner-ring raceway spalling from overload or contamination in the line-contact hertz zone
- outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating
- polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- Mount the 80 mm bore NU316 by induction heating of the inner ring (max 120 °C — the polymer cage sets the ceiling, not the steel); driving it home through the rollers brinells the raceway.
- The NU300 series at 80 mm bore (170×39 mm) is the standard-section cylindrical roller envelope; stepping to a wide-section 22/23 variant changes OD, width and heat generation — it is not a drop-in swap when the housing and speed are fixed.
- Shaft and housing fillets must clear the bearing chamfer so the 39 mm-wide outer ring seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The NU316 shares its ISO 15 envelope with other cylindrical bearings of the same code but is not a drop-in replacement for a ball bearing: it has no axial load capacity in the NU design, and a deep-groove bearing cannot replace its radial-capacity duty.
- The 300/290 kN ratings are SKF catalogue 17000 values for the ECP polymer-cage execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of NU316 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 316 ECP designation when purchasing and match the execution to the speed and temperature requirements.
Frequently asked questions
What are the dimensions and catalogue data of NU316?
The NU 316 ECP is a single-row cylindrical roller bearing with 80 mm bore, 170 mm outer diameter and 39 mm width (3.15 × 6.693 × 1.535 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 300 kN, C0 290 kN, fatigue load limit Pu 36 kN, reference speed 4,300 r/min, limiting speed 5,000 r/min, mass about 3850 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU316 bore code work?
The last two digits of NU316 are bore code 16, so 16 × 5 = 80 mm bore. The 170 mm OD and 39 mm width come from the ISO 15 dimension-series plan, shared with other cylindrical bearings of the same code.
What does the ECP suffix mean on NU316?
ECP stands for a glass-fibre reinforced polyamide cage (PA66), the SKF standard for this size. Alternative executions include ECJ (pressed steel cage) and ECM (machined brass cage), which have different speed and temperature ratings and are separate order numbers.
Can NU316 take axial load?
No — the NU design has no ribs on the outer ring and cannot support axial load in either direction. It is intended for pure radial load with axial location provided by adjacent components. If axial location is required, consider NJ (one-direction) or NUP (two-direction) variants, or pair the NU bearing with a thrust or angular-contact bearing.
How does NU316 compare with a ball bearing of the same bore?
A cylindrical roller bearing has line contact and much higher radial capacity than a ball bearing of the same bore, but it cannot take axial load in the NU design and is sensitive to misalignment (≈ 3–4 minutes of arc). Speed limits are generally lower than deep-groove ball bearings. A ball bearing cannot be dropped into a pure radial cylindrical-roller position without re-checking life and deflection, and vice versa.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.