HK3020 bearing: complete specifications & equivalents
The HK3020 is a ISO 3245 radial bearing sized 30 x 37 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 30 mm |
| Outer diameter D | 37 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 20.9 kN |
| Basic static load rating C0 | 40 kN |
| Fatigue load limit Pu | 4.75 kN |
| Reference speed (thermal) | 8000 rpm |
| Limiting speed (mechanical) | 9000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 38 g |
| Manufacturer designation | HK 3020 |
| Standard | ISO 3245 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle 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. 7.2 drawn cup needle 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 & HK-series range
| Bore d | 1.181 in |
|---|---|
| Outer diameter D | 1.457 in |
| Width B | 0.787 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 3.5 mm |
| Smallest bore in HK-series | 3 mm |
| Largest outer diameter in HK-series | 68 mm |
| Width range across HK-series | 6–38 mm |
| Bore position in HK-series (smallest first) | 20 of 26 |
| Bore above smallest HK-series size | 27 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HK3020 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 HK3020 model number is decoded
For a 30 mm shaft in a thin housing wall, SKF catalogue execution HK 3020 offers a 20 mm wide, 37 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. SKF's HK numbering puts the shaft size first: 30 → Fw 30 mm (the ground, hardened journal), 20 → width 20 mm, with the 37 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.
Typical equipment & failure modes
Common applications
- clutch release mechanisms and cable pulleys
- office equipment and power tool gear trains
- steering column and pedal-box pivots in passenger cars
- idler gears and pulleys in small appliance drives
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- false brinelling of standby equipment under external vibration
Selection pitfalls — read before you substitute
- At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.
- Do not interchange envelope-identical needle families blindly: HK 3020 shares its 30×37×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.
- The 20.9/40 kN ratings and 38 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What limits the service life of a HK 3020?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the HK 3020?
A HK 3020 measures 30 mm bore/Fw × 37 mm outside diameter × 20 mm width (1.181 × 1.457 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.9 kN, static C0 40 kN, fatigue limit Pu 4.75 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 38 g.
How is the HK 3020 designation read?
HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 20 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage.
Can the HK 3020 run on an unhardened shaft?
No. In this execution the 30 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. 7.2 drawn cup needle roller bearings on 2026-09-26. Read our editorial & correction policy.