Screwdriver made from high strength steel strip - which is inserted into ductile steel tube with deformations in wall to grip handle

摘要

Screw-drivers can be produced at low cost by beginning with a flat strip of high strength steel. The width of the strip is equal to the diameter of the head of the screw and its thickness is slightly less than the width of the slot. This steel strip is forced into a tube of ductile steel, which is deformed to an oval cross-section. A small portion of the high strength steel strip projects beyond the end of the tube. The tube is then inserted into a handle where it is retained by local deformation of the tube wall.