Durable Adjustable Counterbore Router Bit | 8mm Shank Design for Screw Holes, Woodworking Boring, and Precision Countersinking
This 8mm shank adjustable counterbore router bit is designed for woodworking screw holes and countersinking. Durable carbide blades ensure smooth, accurate boring and long-lasting performance.

















Features
- 100% brand new and high quality.
- Ideal for making drawers and precision joinery.
- Industrial-grade router bit with hardened steel body.
- Anti-kickback design for safe operation.
- Heat-resistant Teflon® coating.
- High hook & shear angles for smooth, splinter-free cuts.
- Sealed, lubricated bearings for durability.
Specifications
- Material: 45# steel
- Carbide tip: YG6X
- Shank diameter: 8 mm
- Balance tolerance: ±0.003″
- Body: Solid hardened steel
- Blade: Industrial-grade micro-grain carbide
- Cutter: CNC ground to 600-grit mirror finish
- Detailed specifications available in product photos
Reference: Machine Speeds
| Machine | Speed Range | Notes |
|---|---|---|
| Trimming machine | 10,000–30,000 rpm | General cutting |
| Electric router | 9,000–23,000 rpm | 5 speed levels |
| Vertical router | 12,000–24,000 rpm | Low / high gear |
| CNC engraver | Up to 18,000 rpm | Variable frequency |
Diameter vs. Max Speed / Feed
| Diameter (mm) | Max Speed (rpm) | Max Feed (mm/min) |
|---|---|---|
| ≤ 25 | 24,000 | 5,000 |
| 25.1 – 35 | 18,000 | 4,000 |
| 35.1 – 50 | 16,000 | 3,500 |
| 50.1 – 60 | 14,000 | 3,000 |
| 60.1 – 80 | 12,000 | 2,500 |
| ≥ 80 | 10,000 | 2,000 |















