my Old Workshop

How a painful cut led to a great invention

The story goes that back at the turn of the century, P.L. Robertson was setting up his tool stand on a Montreal street corner. P.L. was a “high pitch man”, or street vendor, selling something called the Yankee Screwdriver, which had a spring-loaded spiral shank to put a little extra torque on the screw. Problem was, it was dangerous. As he set up his stand, he slipped, cut his finger, and headed home, swearing he would invent a better way of doing things.

He came up with the Robertson, a square-slot screw which is easier to drive than either a standard-slot or the criss-cross Phillips screw. Before long, he’d patented his invention, developed a line of screwdrivers to use with it, and opened up a factory in Ontario.

Now, some 90 years later, the Robertson is pretty much the standard in Canada, and more and more “square-recess screws” are becoming available in the USA.

Why the popularity? The square head on the screwdriver means you don’t slip when you’re turning the screw. So you don’t easily damage the screw… or your hand. And you can even hold the screw on the end of the driver as you position it in tricky places. So it’s good both for woodworking and parts assembly.

Until recently it was used mainly in Canada, so it had other advantages. Back in the 60s, an American appliance company used Robertson screws to attach the backplate on their products. That way, only their repairman could get inside and fiddle around; the average consumer just wouldn’t have the tools.