Square socket Screwdriver
(1911) Invented by P.L. Robertson (1879-1951)
After badly cutting his hand while using a slot-headed screwdriver, Peter Lymburner Robertson invented the squareheaded screwdriver and screw in 1908. He received the Canadian patent for his invention in 1909. A person could drive a screw more quickly with this new design and the screw was self-centering so only one hand was needed. On top of that, the driver fit more tightly in the screw’s head, thereby reducing the chance of the screwdriver slipping out. The Robertson screw was a big hit! Industry loved it because it sped up production and resulted in less product damage. No one has been able to improve on this design in all the years that have followed!