Millions of craft workers are thankful to Canadian Peter Robertson for inventing the square-head screw that bears his name. The Robertson screw represented a significant advance in the history of fasteners for two practical reasons: it is self-centering (that is, the screw is almost impossible to be driven off-centre because of the indented squared notch into which the screwdriver fits snugly) and the screw can be driven with only one hand. Peter Robertson (1879 - 1951) was a young Ontario-born salesman demonstrating a conventional slotted screwdriver when the tip slipped and cut his hand. Vowing that would not happen again, Robertson developed what he later called “the biggest little invention of the 20th Century so far” – a claim difficult to dispute since by 1908 he had secured the Canadian patent and, later, patents in all major countries. [caption id="attachment_3845" align="alignleft" width="163" caption="Photograph of Peter Lymburner Robertson by Ken Lamb. Public Domain image obtained from Library and Archives Canada."][/caption][caption id="attachment_3847" align="alignright" width="175" caption="Drawing from a patent for Robertson Screw, 1909. Public domain image obtained from Library and Archives Canada."][/caption] Early success was demonstrated by the fact that the Fisher Body Company, which made chassis in Canada for Ford’s Canadian subsidiary, used between 500 and 800 screws for each wooden body of a Model T and, later, Robertson supplied metal screws for the assembly of the metal-bodied Ford Model A. Apparently the use of these screws cut overall vehicle assembly time by nearly two hours! Although over the next many decades the firm prospered, the history of its relationship with Ford is instructive. Ford’s policy was to enter into a licensing agreement with a patent holder and not simply to buy the finished product from the patentee. When this was put forward by Ford, Robertson balked, believing that his long-term interests would be prejudiced, and later Ford would enter into a licensing agreement with a more compliant supplier by the name of Phillips. To this day, although the Robertson screw is dominant in Canada and in several other countries, the Phillips screw and driver has the bulk of the US market for a somewhat similar fastening device. A corporate partnership with a UK firm during World War I was not a complete success, although in World War II the use of a combination square-and-slot screwdriver for assembling the wooden Mosquito bomber was very positive for Robertson, resulting in the largest order the enterprise had ever received. Corporate history buffs may be interested to learn that one of the two current owners of Robertson Inc is Berkshire Hathaway Company – perhaps Warren Buffet is a handyman who appreciates well-functioning tools! Not atypically today, the actual manufacturing is carried out in Zhejian, China. And for those who want to place the invention in a wider context of tools, Witold Rybczynski has done that in his excellent book, One good turn: a natural history of the screwdriver and the screw (Scribner, 2000). Summary by: Richard Potter


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