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Brand:OTOTRI
Product origin:China
Delivery time:3-5 days
Supply capacity:Mass production
HK0608 Drawn Cup Needle Roller Bearing — 6 × 10 × 8 mm, Open End
HK0608 is a small-bore open-end drawn cup needle roller bearing: 6 mm bore (Fw), 10 mm outside diameter, 8 mm outer ring width, mass 2.1 g. It carries 2.01 kN dynamic and 1.73 kN static load in a 2 mm radial wall and runs to 22 000 r/min — the highest speed band in the whole HK range. The cup presses into a 10 mm housing bore and the shaft is the inner raceway, so a 6 mm shaft needs no bearing seat at all. GCr15 rollers, steel cage, P0/P6, from 100 pieces.
HK0608 Specifications
| Designation | HK0608 |
| Type | Drawn cup needle roller bearing, open both ends, caged |
| Bore diameter Fw | 6 mm |
| Outside diameter D | 10 mm |
| Outer ring width C | 8 mm |
| Corner radius r1,2 min | 0.4 mm |
| Dynamic load rating Cr | 2.01 kN |
| Static load rating C0r | 1.73 kN |
| Fatigue load limit Pu | 0.18 kN |
| Reference speed | 20 000 r/min |
| Limiting speed | 22 000 r/min |
| Mass | 0.0021 kg (2.1 g) |
| Outer ring | Cold-rolled steel cup, case hardened |
| Rollers | GCr15 (100Cr6), ground, gauge-sorted |
| Cage | Steel |
| Tolerance class | P0 standard, P6 on request |
| Shaft requirement | 58–62 HRC, Ra ≤ 0.2 µm, h5/h6 |
| Housing bore | N7 press fit |
| Operating temperature | −30 °C to +120 °C (grease-dependent) |
| Matched inner ring | None in this size — the shaft must be hardened |
| Matched seal | G 6X10X2 S |
| MOQ | 100 pcs |
Small-Bore HK Series — 17 Sizes from 3 mm to 12 mm
| Designation | Fw (mm) | D (mm) | C (mm) | Cr (kN) | C0r (kN) | Pu (kN) | Speed ref / limit (r/min) | Mass (kg) |
|---|---|---|---|---|---|---|---|---|
| HK 0306 TN | 3 | 6.5 | 6 | 1.23 | 0.88 | 0.088 | 24 000 / 26 000 | 0.001 |
| HK 0408 | 4 | 8 | 8 | 1.76 | 1.37 | 0.14 | 22 000 / 26 000 | 0.002 |
| HK 0509 | 5 | 9 | 9 | 2.38 | 2.08 | 0.22 | 22 000 / 24 000 | 0.002 |
| HK 0606 | 6 | 10 | 6 | 1.72 | 1.29 | 0.132 | 20 000 / 22 000 | 0.0015 |
| HK 0608 | 6 | 10 | 8 | 2.01 | 1.73 | 0.18 | 20 000 / 22 000 | 0.0021 |
| HK 0609 | 6 | 10 | 9 | 2.81 | 2.7 | 0.285 | 20 000 / 22 000 | 0.0025 |
| HK 0709 | 7 | 11 | 9 | 3.03 | 3.05 | 0.325 | 20 000 / 22 000 | 0.0026 |
| HK 0808 | 8 | 12 | 8 | 2.7 | 2.75 | 0.285 | 19 000 / 22 000 | 0.0027 |
| HK 0810 | 8 | 12 | 10 | 3.69 | 4.05 | 0.44 | 19 000 / 22 000 | 0.003 |
| HK 0908 | 9 | 13 | 8 | 3.52 | 3.9 | 0.415 | 18 000 / 20 000 | 0.003 |
| HK 0910 | 9 | 13 | 10 | 4.13 | 4.8 | 0.53 | 18 000 / 20 000 | 0.004 |
| HK 0912 | 9 | 13 | 12 | 5.12 | 6.4 | 0.72 | 18 000 / 20 000 | 0.0046 |
| HK 1010 | 10 | 14 | 10 | 4.29 | 5.3 | 0.57 | 18 000 / 20 000 | 0.0041 |
| HK 1012 | 10 | 14 | 12 | 5.39 | 6.95 | 0.78 | 18 000 / 20 000 | 0.0048 |
| HK 1015 | 10 | 14 | 15 | 6.6 | 9 | 1.02 | 18 000 / 20 000 | 0.006 |
| HK 1210 | 12 | 16 | 10 | 4.84 | 6.4 | 0.71 | 16 000 / 18 000 | 0.0046 |
| HK 1212 | 12 | 18 | 12 | 6.27 | 7.35 | 0.85 | 16 000 / 18 000 | 0.009 |
All open-end HK types. HK 0306 TN carries a TN suffix (plastic cage) and a 6.5 mm outside diameter — do not confuse it with a 6 mm bore standard cup. Sealed (RS / 2RS) and heavy-duty (HN) versions of these sizes exist and are quoted on request.
Same 6 mm Bore, Four Choices
| Designation | Type | D × C (mm) | Cr (kN) | C0r (kN) | Mass (kg) | Choose it when |
|---|---|---|---|---|---|---|
| HK0606 | open, thin | 10 × 6 | 1.72 | 1.29 | 0.0015 | Minimum width — tightest axial space |
| HK0608 | open, standard | 10 × 8 | 2.01 | 1.73 | 0.0021 | The balanced default for a 6 mm shaft |
| HK0609 | open, wide | 10 × 9 | 2.81 | 2.7 | 0.0025 | +40% dynamic capacity, same 10 mm OD |
| BK0609 | closed one end | 10 × 9 (C1 7.4) | 2.81 | 2.7 | 0.0026 | Shaft end, grease retention, dirt exclusion |
The 6 mm bore family is compact, so the decision is almost always axial space versus capacity. HK0606 exists for a 6 mm wide pocket; HK0609 gives 40% more dynamic load without changing the 10 mm OD; BK0609 is the closed-end version for a shaft that terminates inside the housing (C1 7.4 mm, so the shaft can enter 7.4 mm).
Reading the Numbers at This Size
| Symbol | Value | What it means in your design |
|---|---|---|
| Cr | 2.01 kN | Dynamic rating at 1 million revolutions. At 2 kN the bearing is at its limit, not in its comfort zone |
| C0r | 1.73 kN | Static rating — the thin section means press-fit stress and shock matter proportionally more here than on large sizes |
| Pu | 0.18 kN | Fatigue limit — with light preloads and vibration, running below this gives effectively unlimited life |
| 20 000 / 22 000 r/min | — | High for the range because the rollers are small and light; the practical limit is usually the grease, not the bearing |
| 2 mm wall | — | A 6 mm bore ball bearing needs about 4.5 mm of radial space; this needs 2 mm |
Small bearings are less forgiving than large ones: at this size a 0.01 mm bore distortion is a significant fraction of the radial internal clearance, so housing roundness and press-fit interference matter more than the catalogue numbers suggest. Press into a round, rigid bore — a split or thin-wall plastic housing will ovalise the cup and the bearing will drag.
Typical Applications
| Application | Position | Why HK0608 |
|---|---|---|
| Micro DC motors and steppers | Shaft support at the commutator end | 10 mm OD, runs to 22 000 r/min |
| Printers, copiers, card readers | Feed roller and cam pivot | Quiet, low friction torque, no inner ring |
| Medical and lab instruments | Guide and pivot pins | Repeatable low-friction motion |
| Fishing reels | Handle shaft support | Very low cost at volume |
| Hobby and RC drives | Gearbox pinion support | Fits a 6 mm shaft with a plain 10 mm bore |
| Small gearboxes and actuators | Planet and idler pins | 2 mm wall in a tight centre distance |
| Power tools | Small output shafts | Press fit, no seat machining |
Shaft, Housing and Installation
- Shaft: 58–62 HRC, ground to Ra ≤ 0.2 µm, h5/h6. No inner ring exists in this size, so this is not optional.
- Housing: N7 press fit in a rigid, round bore; R7 for thin-wall aluminium; chamfer 0.3 × 20°; bore depth at least 8 mm.
- Press on the stamped face with a flat arbor sized to the cup — never load the cage, and never press on the seal lip.
- Sealing: G 6X10X2 S lip seal where the housing face needs external sealing, or specify an RS / 2RS bearing.
- Lubrication: a light grease fill (20–25% of free space). Above 15 000 r/min use oil or a low-viscosity grease; over-greasing is the usual cause of overheating at this size.
- Handling: 2.1 g bearings are easy to drop and easy to distort. Keep them in the original tube until the press is ready.
Quality Control on Every Batch
- 100% dimensional check on Fw, D and C, with SPC record per lot
- Case depth and hardness verified on the cup
- Roller sorting to 1 µm gauge classes
- Rotation torque and noise sampled per lot
- Material certificate 3.1 and inspection report with the shipment
- Anti-rust film, individual bag, carton
Packing, MOQ and Delivery
10 pcs per bag, 2 000 per carton, cartons on a pallet or in a plywood case. MOQ is 100 pcs for stock sizes. Stock ships in 3–7 days; production orders 20–30 days. Air, sea LCL and FCL available.
Frequently Asked Questions
What are the dimensions of HK0608?
6 mm bore (Fw), 10 mm outside diameter, 8 mm outer ring width and 2.1 g mass.
What is the load rating of HK0608?
Dynamic 2.01 kN, static 1.73 kN and a fatigue load limit of 0.18 kN.
How fast can HK0608 run?
Reference speed 20 000 r/min and limiting speed 22 000 r/min. In practice grease life sets the ceiling before the bearing does.
Can I use an inner ring with HK0608?
No. The catalogue offers no LR/IR inner ring for a 6 mm bore, so the shaft itself must be hardened to 58–62 HRC and ground.
HK0606, HK0608 or HK0609?
All three are 6 mm bore × 10 mm OD. HK0606 is 6 mm wide (minimum axial space), HK0608 is 8 mm wide, HK0609 is 9 mm wide with 2.81 kN instead of 2.01 kN. Pick by the axial room you have.
Which brands interchange with HK0608?
HK0608 is a standardized metric designation and interchanges with the same code from INA/FAG, SKF, NTN, NSK and Koyo.
Need HK0608 or a small-bore alternative?
Tell us the shaft hardness, the axial space and the quantity — we reply with price, lead time and a drawing within 24 hours on working days.