Peter Lymburner Robertson (1879-1951) is a Canadian inventor of the square-drive screw, first produced in his Milton, Ontario factory in 1908. Peter also wrote The Gold Standard, a book advocating gold-backed money. The Robertson factory is still operating today. More information can be found in the books "P.L. Inventor of the Robertson Screw" by Ken Lamb, and "Milton Area Biographies V.2."
