Drill for making bores through wood, chipboard or plastics has guide peg at head end, entering pilot bore and cutting head on fluted shaft fitting into socket with screw thread

摘要

The cutting head (8) of the drill (1) has a central projecting peg (10) and forms the head end of a shaft (2) with two flutes (3,4) separating spiral surfaces of uniform external diameter (5,6). The tail end of the fluted shaft fits into a guide portion (20) of a socket (11) with a threaded bottom end (21). The extreme end of the shaft (14) has a male thread and screws into the threaded bottom of the socket.