Försänkare

A försänkare, often translated as a countersink or countersink bit in English, is a cutting tool used to create a conical recess in a pre-drilled hole. This recess allows the head of a screw or bolt to sit flush with or below the surface of the material being fastened. This is often done for aesthetic reasons, to prevent snagging, or to allow for subsequent covering of the fastener.

Försänkare typically have multiple cutting edges and are made from hardened steel. They are commonly used in woodworking, metalworking, and plastics manufacturing. The angle of the conical recess is usually standardized to match common screw head angles, such as 90 or 120 degrees, though other angles are available.

When using a försänkare, it is rotated at a relatively slow speed, often in conjunction with a drill or a milling machine. The depth of the countersink can be controlled by the user, ensuring the fastener head sits at the desired level. For precise depth control, drill stops or depth collars can be employed. The material removed by the försänkare is in the form of small chips. There are various types of försänkare, including those with a pilot, which guides the bit into the pre-drilled hole, and those without.