Method of and tool for thread mill drilling.

摘要

The method is for forming a threaded hole (20) in a workpiece and comprises providing an elongated tool (24) having a drilling face (64) at one end and a thread milling profile along the side. The tool is rotated about a longitudinal axis while shifting it axially to carry the drilling face against and into a workpiece to form a hole. While the tool is rotated the axis of rotation is displaced radially at a distance equal to the thread depth to be formed. While the tool is rotated its axis of rotation is moved orbitally around the hole to mill threads in the wall. The axis of rotaiton is rotated radially back to the centre of the hole and the tool is then retracted from the hole.