Countersink drill bit Wiha 79186 B5

The Wiha 79186 B5 countersink drill bit set contains five precision-ground countersinks designed to produce clean, conical recesses for screw heads and fasteners. Each countersink measures 35 mm in overall length and is supplied in a compact storage box for organized transport and easy access. The set covers common sizes used in joinery and metalwork, providing consistent chamfering and deburring for wood and metal substrates.

Advantages

Each bit in the set is manufactured to provide accurate cone angles and smooth cutting edges that reduce splintering in wood and minimize burr formation in metal. The uniform length simplifies depth control while the included storage box protects cutting edges and keeps sizes sorted. The set’s range of diameters makes it straightforward to match countersink size to screw head or plug diameter for a flush finish.

Suitable for

• Creating conical recesses for wood screws in furniture assembly
• Deburring and chamfering metal sheet edges before fastening
• Preparing holes for plug or dowel installation in cabinetry
• General workshop and maintenance tasks requiring precise recessing

Key specifications

• Set composition: 5 countersink drill bits
• Available diameters: 6.3 mm, 8.3 mm, 10.4 mm, 12.4 mm, 16.5 mm
• Overall length per bit: 35 mm
• Material compatibility: wood and metal
• Storage: compact protective box included

How to use

Select the countersink size that matches the screw head or plug diameter, clamp the workpiece securely, and mark the hole center. Fit the countersink into a suitable drill chuck or holder, align perpendicular to the work surface, and apply steady, moderate feed while running the drill at an appropriate speed for the material. Withdraw occasionally to clear chips and check the recess depth until the screw head sits flush or at the desired depth.

Usage recommendations

For best results, use light cutting oil when countersinking ferrous metals and choose lower drill speeds for larger diameters or harder materials. Always wear appropriate eye protection and secure small workpieces in a vice or clamp to prevent movement during drilling.