NK43-30 bearing: complete specifications & equivalents
The NK43-30 is a DIN 616 radial bearing sized 43 x 53 x 30 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 43 mm |
| Outer diameter D | 53 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 40.2 kN |
| Basic static load rating C0 | 90 kN |
| Fatigue load limit Pu | 11.2 kN |
| Reference speed (thermal) | 9500 rpm |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 130 g |
| Manufacturer designation | NK 43/30 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without 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. 7.3 machined rings with flanges, without 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 & NK-series range
| Bore d | 1.693 in |
|---|---|
| Outer diameter D | 2.087 in |
| Width B | 1.181 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 5 mm |
| Smallest bore in NK-series | 5 mm |
| Largest outer diameter in NK-series | 130 mm |
| Width range across NK-series | 10–40 mm |
| Bore position in NK-series (smallest first) | 29 of 46 |
| Bore above smallest NK-series size | 38 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK43-30 model number is decoded
In SKF catalogue PUB BU/P1 17000, NK 43/30 designates a flanged, machined outer ring filled with needle rollers and a cage for a 43 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 43 mm under-roller diameter and the 30 mm width, with the 53 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 40.2/90 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. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 53 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.
Typical equipment & failure modes
Common applications
- guide rollers running on hardened tracks
- swing arms and lever pivots with oscillating duty
- cam followers built up from separate components
- crank pins and eccentrics where the hardened journal is the raceway
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
- false brinelling of standby equipment under external vibration
- rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away
Selection pitfalls — read before you substitute
- At 43 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 43 mm seats can bend past the compensation range long before the load rating is exhausted.
- The quoted 40.2/90 kN ratings are SKF catalogue values for this exact execution (NK 43/30); 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 40.2/90 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Is the NK 43/30 sealed?
No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty.
Which dimensions does the NK 43/30 have?
A NK 43/30 measures 43 mm bore/Fw × 53 mm outside diameter × 30 mm width (1.693 × 2.087 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 90 kN, fatigue limit Pu 11.2 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 130 g.
What does NK 43/30 mean in SKF part numbering?
NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 43 mm and width 30 mm, OD 53 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
Does the NK 43/30 need a hardened and ground shaft?
No. In this execution the 43 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring on 2026-09-26. Read our editorial & correction policy.