NKI20-16 bearing: complete specifications & equivalents
The NKI20-16 is a DIN 616 radial bearing sized 20 x 32 x 16 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 20 mm |
| Outer diameter D | 32 mm |
| Width B | 16 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 15.4 kN |
| Basic static load rating C0 | 24.5 kN |
| Fatigue load limit Pu | 2.9 kN |
| Reference speed (thermal) | 16000 rpm |
| Limiting speed (mechanical) | 19000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 48 g |
| Manufacturer designation | NKI 20/16 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring); 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 & NKI-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 1.26 in |
| Width B | 0.63 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 6 mm |
| Smallest bore in NKI-series | 5 mm |
| Largest outer diameter in NKI-series | 130 mm |
| Width range across NKI-series | 12–40 mm |
| Bore position in NKI-series (smallest first) | 9 of 30 |
| Bore above smallest NKI-series size | 15 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKI20-16 model number is decoded
SKF lists NKI 20/16 in the machined-ring needle roller bearings with inner ring with boundary dimensions 20×32×16 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 20 mm d and 16 mm B, the 32 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 15.4/24.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 16 mm width and s offset dimensions against the open execution before reusing an existing bore.
Typical equipment & failure modes
Common applications
- agricultural implement pivots and cutter heads
- electric motor armature shafts with ground seats
- printing and paper-handling rollers
- gearbox shafts where the journal cannot be hardened on site
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- cage pocket wear and roller skew after sustained operation with too little radial preload
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- electrical erosion on VFD-driven shafts without brush or insulated mounting
- inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact
Selection pitfalls — read before you substitute
- On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- The quoted 15.4/24.5 kN ratings are SKF catalogue values for this exact execution (NKI 20/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.
- The 15.4/24.5 kN ratings and 48 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Does the NKI 20/16 need a hardened and ground shaft?
Yes — that is the point of this family. The NKI 20/16 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable.
What mounting mistakes ruin a NKI 20/16?
Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth.
Is the NKI 20/16 sealed?
No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number.
Which dimensions does the NKI 20/16 have?
A NKI 20/16 measures 20 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.787 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.4 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 48 g.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring on 2026-09-26. Read our editorial & correction policy.