Countersink Drill Bits

Whether it is used in a drill, drill press, milling machine or lathe, countersinks cut conical holes from a wood, plastic or metal base material in order to allow the head of a countersunk screw or bolt to sit flush or below the surface of the material. They can also be utilized to remove burrs left behind from drilling or tapping operations in order to remove sharp edges and create a clean, finished look. AFT provides countersink drill bits in several sizes and styles. You'll find both carbide and high speed steel double-ended carbide center drills, deburring tools, piloted and unpiloted countersinks as well as assorted countersink sets from HTC and Norseman Drill & Tool. Filter your search with the menus to the left or contact us for help with finding the perfect high speed steel countersink for your project.

Two Styles of Countersinks

There are two main countersink styles, fluted and zero flute. Fluted countersink cutters have a short shank, an elongated cylinder and a conical tip with anywhere from one to five cutting edges. After an initial pilot hole is drilled, the fluted cutter is used to create a countersink hole for a flat head screw with head angle that corresponds to the angle of the countersink cutter. The most common angle sizes are 82 and 90 degrees, but 60, 100, 110 and 120-degree angled points are also available.

As the name implies, zero-flute cutters, also known as cross-hole countersinks, have no flutes, but rather an angled hole is bored through the cone. As the bit rotates, the back edge of the hole makes the cut while also ejecting chips as it spins. Cross-hole countersinks are useful for creating clean countersinks in softer materials, but they excel in deburring applications.

Drill Bit Resources