| 摘要 |
A combined cross-head screwdriver and countersinking tool comprises a screwdriver tool (10) which is secured permanently to a milling-type countersinking tool (12). The two tool portions are co-axially aligned. The combined tool is suitable for insertion into a chuck of an electric or hand-operated drill. For safety, the countersinking tool (12) comprises cutting blades (16) which are orientated to cut in anti-clockwise rotation of the tool. In use of the tool, the tool is rotated anti-clockwise in order initially to drill a hole in softwood by means of the screwdriver tool (10), and subsequently to countersink the entry to the hole. The tool is then removed from the hole formed, a screw inserted into the hole, and the tool rotated clockwise to drive a screw into the workpiece. The reverse orientation of the countersinking cutters ensures that an operator's fingers will not be cut should the screw be held upon initial insertion.
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