By Porter Lang
Look into the head of a screw. If the socket is a square, and the sides taper to a point, you are looking at a Canadian habit.
That is the short version. The longer one has a salesman, a cut hand, a carmaker who wanted more than he was offered, and a set of dates that do not line up. We read four sources and set them next to each other. Wikipedia is an open encyclopedia. The Dictionary of Canadianisms on Historical Principles, a university-run reference, covers the word. Ingenium, Canada’s museums of science and innovation, has a short biography page. Wikipedia also has a separate article on the man himself.
What the socket does
Wikipedia’s article on the screw lists the advantages in plain terms. The tapered socket makes the driver easy to insert and holds the screw on the tool without the user holding it, which means it can be used one-handed. The screws centre themselves and reduce cam-out, which is the driver slipping out of the recess under load. They are easier to remove when painted over or rusted. They can stop a power tool when set. In industry, the article says, they speed up production and reduce damage to the product.
The Dictionary of Canadianisms quotes a 2000 source making the point in one sentence: you can shake a Robertson screwdriver, and the screw on the end will not fall off.
Who got there first
Wikipedia says an earlier design existed. U.S. patent 161,390, issued to Allan Cummings of New York City on 30 March 1875, covered square and triangle socket wood screws. Wikipedia’s article on the inventor adds that it was never a commercial success. Many drive designs of the 1860s to the 1890s, the screw article says, were never manufactured widely because they were hard and expensive to produce.
What changed, according to the screw article, was the taper. In 1908, it says, Robertson designed the socket’s taper and proportions so that the heads could be cold formed easily. Cold forming, stamping the head in a die, is still the most common way to make them. The Dictionary of Canadianisms says the same thing in other words: other square-socket designs existed, but Robertson’s tapered socket let manufacturers cold-form the heads cheaply.
The salesman
Ingenium says Peter Lymburner Robertson, born in 1879 in Seneca, in what is now Haldimand County, Ontario, was a sales representative in Canada for a Philadelphia tool company. During a demonstration in downtown Montreal, it says, his screwdriver blade slipped out of a slotted screw and cut his hand. He then designed a screw with a square socket so the blade would sit securely.
Wikipedia’s biography agrees on the employer, naming it as North Brothers of Philadelphia and saying he travelled for them in eastern Canadian territories. It does not name the city where his hand was cut. Only one of our sources has the Montreal detail, so we pass it on as Ingenium’s account and no more.
Dates in order
- 30 March 1875: the Cummings patent, according to Wikipedia.
- 1906: Robertson invents the screw and screwdriver, according to Wikipedia’s screw article.
- 1907: a Canadian patent, number CA103387, according to the same article. Wikipedia’s biography gives 1907 as the year he founded the company, in Hamilton, Ontario.
- 1908: the Milton, Ontario factory, according to Ingenium and the biography. The screw article gives 1908 as the year of the taper design.
- 1909: the patent, according to the biography and the Dictionary of Canadianisms.
- 1910: the date in a 1998 newspaper quotation in the dictionary. The dictionary itself notes it conflicts with 1908 and 1909.
- 1911: a U.S. patent, number 1,003,657, for a manufacturing machine, according to the screw article.
Side by side
Four pieces of work, five years. The screw article says 1906 for the invention and 1907 for the Canadian patent. The dictionary says 1908 for development and 1909 for the patents. The biography says 1909 for the patent. A newspaper in 1998 said 1910. Our reading: the invention, the first patent, the factory and the second patent were probably separate steps, and each source is naming a different one. That is our inference, and none of the pages says it.
The carmaker
Wikipedia’s screw article says Ford found that the screws saved considerable time on the Model T line. Robertson refused to license the design. Ford, it says, then limited their use to his Canadian division, because he could not guarantee a supply. The biography tells it a little differently: Fisher Body used over 700 Robertson screws in the Model T, and Ford sought an exclusive United States licence, which Robertson declined. Ingenium says Ford’s Detroit executives wanted a say in where product development happened, and that Robertson left without a deal. Three accounts of the same refusal, with three different reasons for it.
The screw article makes the same point about why the design stayed local. Robertson would not license it, and that limited supply. Adoption has grown, it says, as patents expired and the advantages became known. The Dictionary of Canadianisms says that outside Canada the term is most common in the United Kingdom and more common in other Commonwealth countries than in the United States, where it is rare. It also says the company was bought by an American conglomerate in 1968, with no further detail.
Reading a modern screw
Here is the practical bit. Wikipedia says the square-drive screw has “all but replaced the Robertson screw proper”. Modern square drives have parallel sides, it says, while the original Robertson socket is tapered. Our reading: when a package says “square drive”, ask whether the socket is the tapered kind. The article does not say how the two interchange, and neither do we.
What kind of sources these are
Wikipedia, twice: open and edited by many hands, and summarised by us from a fetch tool. A university dictionary of Canadian English, which is careful about dates and says where they conflict. A national museum body’s biography page, written for the public. None of them is a patent document, and we did not read the patents.
What we left out
A price saved per vehicle, quoted by one source. The loan that brought the factory to Milton. A job count. Later honours, apart from noting that the sources list several. Anything about the company’s later ownership beyond the 1968 line.
Questions a buyer would ask
Is this the tapered socket or a parallel-sided square? What size is it, and what colour driver does it call for? Who made it, and where? And if a hardware seller gives you a date for the invention, which of the dates above is it?
Roam first. Shop later.