Murtotappi

Murtotappi is a term originating from Finnish and can be translated to "break tap" or "snap tap." It refers to a type of tool specifically designed for the removal of broken screw or bolt shafts that have become lodged in a workpiece. These tools are essential in situations where a fastener has snapped off flush with the surface, leaving no part accessible for conventional gripping or turning.

The design of a murtotappi typically involves a reverse threaded spiral fluting. To use it, a hole is first drilled into the center of the broken shaft. The murtotappi is then inserted into this pre-drilled hole and turned counter-clockwise. As it is turned, the reverse threads bite into the metal of the broken shaft, and with continued rotation, they exert a torque that unscrews and removes the broken piece.

Murtotapit come in various sizes to accommodate different diameters of broken fasteners. They are commonly found in sets, often made from hardened steel to withstand the forces involved in extracting stubborn broken parts. The effectiveness of a murtotappi depends on the proper drilling of the pilot hole and applying steady, controlled force during operation. It is a crucial tool for mechanics, machinists, and DIY enthusiasts dealing with damaged fasteners.