This month's mystery item is a screw-holding screwdriver, the mechanics of which are really quite simple. The metal ring between the handle and the stem turns to open and close the head. With the tool in the closed position, a screw is placed on the end of the head. The ring is then turned, opening the head and securing the screw.

To enlarge the pic shown click here. To view a closeup of the head, click here.

This 1951 Mechanix ad shows how a screw-holding screwdriver is used. These tools are still made today in a variety of forms. Ours was made by Trimble & Fink around 1925. Click here to enlarge ad.