P.L. Robertson Manufacturing Company, The

The first firm in the world to produce socket-head screws, the P.L. Robertson Manufacturing Company was formed in Hamilton in 1907 and relocated here the following year. It was established by an Ontario inventor Peter Lymburner Robertson and, using an ingenious process he had developed to punch square holes into cold metal, it manufactured the innovative new screw for industrial markets. In its first two decades the company steadily expanded operations. By 1930, when the last patent on the Robertson screw and the equipment used in its manufacture expired, the firm had already begun to diversify its products. Now operated as the Robertson Whitehouse Company, it has become one of the largest manufacturers of light fasteners, including the original Robertson screw, in North America.


At the site of the former factory, 97 Bronte Street, Milton

Region: Greater Toronto Area

County/District: Regional Municipality of Halton

Municipality: Town of Milton