Precision HSS Counterbore Drill Bit for Flat Bottom Recesses

Create clean, accurately aligned recesses for flush-fitting fasteners. This HSS counterbore bit uses an integrated pilot to guide the cutter and produce a concentric flat-bottom hole. Available in M3 to M8 sizes, it suits machinists, metalworkers, repair technicians, and experienced DIY users. The high-speed steel construction supports machining compatible steel, aluminum, copper, and cast iron.

Key Features

• Pilot tip helps keep the recess centered over the existing hole
• Multi-flute cutter creates a smooth, flat-bottom finish
• Counterbore end mill sizes support M3 to M8 fasteners
• Straight shank fits compatible milling machines and drill equipment

Why Choose Our Precision HSS Counterbore Drill Bit

Unlike standard countersink cutters that form angled recesses, this tool creates a flat seat for compatible bolt and screw heads. The built-in pilot improves alignment and reduces the need to reposition separate tools. Its HSS construction offers dependable toughness and wear resistance for regular workshop use.

Perfect For

Ideal for metal fabrication, machinery repair, mold making, bolt-head recesses, spot facing, countersunk assemblies, and precision workshop projects.

How to Use

Drill the correct pilot hole, secure the workpiece, and install the matching pilot counterbore cutter. Machine at a suitable speed with steady feed and appropriate cutting fluid. Confirm size and equipment compatibility before use.

Product Specs

Material: High-speed steel
Size options: M3 to M8
Cut profile: Flat bottom
Type: Piloted counterbore milling cutter

Create Cleaner Fastener Recesses

Order the Precision HSS Counterbore Drill Bit and achieve accurate, professional-looking results on compatible machining projects.