HK2820 bearing: complete specifications & equivalents
The HK2820 is a ISO 3245 radial bearing sized 28 x 35 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 28 mm |
| Outer diameter D | 35 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 21.3 kN |
| Basic static load rating C0 | 36 kN |
| Fatigue load limit Pu | 4.4 kN |
| Limiting speed (mechanical) | 5500 rpm |
| Mass | 38 g |
| Manufacturer designation | HK2820 |
| Standard | ISO 3245 |
| Catalog version | CAT. No. 2203-3/E 2024 |
| Last verified | 2026-09-25 |
Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (CAT. No. 2203-3/E 2024); 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 & HK-series range
| Bore d | 1.102 in |
|---|---|
| Outer diameter D | 1.378 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 | 58 mm |
| Width range across HK-series | 6–38 mm |
| Bore position in HK-series (smallest first) | 19 of 24 |
| Bore above smallest HK-series size | 25 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK2820 model number is decoded
The NTN HK2820 — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 28 mm is Fw, the under-roller (shaft journal) diameter; 35 mm and 20 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. This cup size is common in power-tool intermediate shafts — drills, saws, grinders — where the gearbox casing is magnesium or aluminium and the cup is pressed into a steel insert. If the shaft sees axial float, allow for it in the housing width — the cup cannot guide the shaft axially, and a shaft that walks will eventually hammer the open end of the shell.
Typical equipment & failure modes
Common applications
- printing press cylinder journals
- machine tool feed drive supports
- marine steering and linkage shafts
- dirty environments where the open ends rely entirely on the housing seals
Known failure patterns
- fretting of the cup outer surface in a soft or worn housing seat
- scoring of the needle rollers from abrasive contamination past the open ends
- brinelling of the drawn cup from hammer blows during press-in mounting
Selection pitfalls — read before you substitute
- The 20 mm wide section of HK2820 gains rating through longer rollers at 28 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 28×35 mm narrow variant.
- The HK2820 drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.
- Pressing HK2820 (28 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.
- With no suffix letters, HK2820 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 28×35×20 mm match exactly — suffix conventions for cage and shell variants differ between makers.
Frequently asked questions
Can a HK2820 needle roller bearing carry axial load?
No. Drawn-cup needle roller bearings like HK2820 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement.
Does HK2820 need a hardened shaft?
Either the 28 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR22x28x20.5) so a standard unhardened shaft can be used.
What are the dimensions of a HK2820 needle roller bearing?
A HK2820 drawn-cup needle roller bearing has a 28 mm shaft diameter (Fw, under-roller diameter), 35 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway.
What does Fw mean on a HK2820 drawn-cup bearing?
Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2820, Fw = 28 mm, so the shaft must be machined to 28 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted.
Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.