What Do Distributors Fear Most?

Customer complaints: "This drill bit went dull after 50 holes."

Then you have to explain it, replace the item, pay for shipping, and the customer may still not be satisfied.

This Four Flute Countersink Drill Bit solves that problem. One bit can make over 1000 holes. We have tested it-over a thousand holes without breaking.

Why Does It Last So Long?

First, the blade is made of 6542 steel. This is not regular HSS steel. It resists high heat and wear. The design uses four flutes. The four cutting edges work together, so each edge bears less force and wears more slowly. This is basic physics.

Second, we inspect every production step-from incoming raw materials, machining, heat treatment, to final packing. Defective products are removed before leaving the factory. Every Four Flute Countersink Drill Bit is fully inspected before shipment.

Third, the blade is replaceable. When the center drill becomes dull, simply unscrew it and replace it. There is no need to discard the entire tool. This helps reduce costs.

Models and Matching Screws

Please refer to the table below:
• Model 2.8×8mm: countersink diameter 8mm, center drill 2.8mm
• Model 4.0×10mm: countersink diameter 10mm, center drill 4.0mm
• Adjustable length: 12–35mm
• Center drill length: 60mm

How to match screws:
• 2.8×8mm fits screw heads smaller than 8mm, with thread diameter 3.2–3.6mm
• 3.2×8mm fits thread diameter 3.6–4.2mm

We also offer sets. The 8mm set includes five pieces: 2.8, 3.0, 3.2, 3.5, and 4.0 × 8mm. Weight is 470g.
The 10mm set also includes five pieces in the same sizes × 10mm. Weight is 480g.

OEM and Usage Tips

We support OEM service. Want your own brand logo? Yes. Have your own drawings? We can produce them. Custom samples take 1 to 4 weeks.

Do not extend the center drill excessively. Use a drill of 18V or higher.

Product Parameters

Model	Countersink Dia.	Center Drill Dia.	Center Drill Length	Adjustable Length	Weight (each)
2.8×8mm	8mm	2.8mm	60mm	12–35mm	11.2g
2.8×10mm	10mm	2.8mm	60mm	12–35mm	11.2g
3.2×8mm	8mm	3.2mm	60mm	12–35mm	11.2g
3.2×10mm	10mm	3.2mm	60mm	12–35mm	11.2g
3.5×8mm	8mm	3.5mm	60mm	12–35mm	11.2g
3.5×10mm	10mm	3.5mm	60mm	12–35mm	11.2g
4.0×8mm	8mm	4.0mm	60mm	12–35mm	11.2g
4.0×10mm	10mm	4.0mm	60mm	12–35mm	11.2g