Ever tried driving a flat-head screw into a piece of tough oak while balanced on a ladder? It’s a nightmare. The driver slips. You gouge the wood. Maybe you even stab your thumb. For decades, this was just "work." Then came one guy and one screwdriver that should have changed everything, but instead became a case study in stubbornness and missed opportunities.
That guy was P.L. Robertson. The screwdriver was the square-drive.
Most people today use Phillips or Torx, but the story of the Robertson screwdriver is a wild ride through Canadian industrial history, a failed deal with Henry Ford, and a design that is technically superior to almost anything else on your workbench. It isn't just about a tool. It's about how a single person's refusal to give up control can stop a world-changing invention from going global.
The Night a Flat-Head Slipped
The year was 1906. Peter Lymburner Robertson, a tool salesman from Ontario, was demonstrating a spring-loaded screwdriver.
The blade slipped.
It sliced his hand open. Most people would have just cursed and reached for a bandage, but Robertson got angry. He realized the fundamental flaw in the slotted screw—it has no centering mechanism. There is nothing keeping the driver in the hole. He went back to his workshop and designed a cold-headed screw with a square socket.
He didn't just invent a screw; he invented a system.
The Robertson screwdriver fits so snugly into the screw head that you can hold the tool horizontally and the screw won't fall off. It doesn't "cam out." If you've ever used a Phillips head and heard that horrible zip-crunch sound as the metal shreds, that's cam-out. Robertson’s design was specifically built to stop that. By 1908, he had his patent. He set up a factory in Milton, Ontario, and for a brief moment, it looked like he was going to rule the world.
Why Henry Ford Almost Made it Famous
Efficiency is everything in manufacturing.
👉 See also: How Axes Coordinate Systems Work (And Why Your Data Depends on Them)
When Henry Ford was ramping up the Model T, he found that Robertson screws saved him a massive amount of time on the assembly line. They didn't slip. They didn't damage the car's bodywork. He started using them by the hundreds of thousands in his Canadian plants.
But Ford was a control freak.
He wanted to license the patent so he could manufacture the screws in his own factories to ensure his supply chain was bulletproof. Robertson, who was equally protective of his "baby," refused. He had seen what happened to other inventors who lost control of their patents. He said no.
Ford was livid. He basically told Robertson that if he couldn't control the production, he wouldn't use the screw at all. Ford switched back to other fasteners and eventually threw his weight behind a man named Henry Phillips in the 1930s. Because Robertson wouldn't budge on his licensing terms, the square-drive remained a Canadian specialty while the rest of the world adopted the (arguably inferior) Phillips head.
The Physics of Why It’s Better
Let's get technical for a second.
The Phillips head was actually designed to cam out. Back when automated assembly lines used primitive torque limiters, the screw needed to reject the driver so the motor wouldn't strip the threads or snap the head off. The sloped sides of a Phillips head push the driver up and out once resistance reaches a certain point.
The Robertson screwdriver does the opposite.
It has a slight taper—about three degrees. This taper creates a "clinging" fit. When you apply torque, the driver seats deeper. It’s pure physics. You can drive a three-inch Robertson screw into a pressure-treated 4x4 with one hand. You try that with a Phillips and you'll be leaning your entire body weight onto the drill just to keep the bit from skipping.
Why the world uses Phillips anyway
- Accessibility: Phillips let anyone make the screws. Robertson didn't.
- The "Good Enough" Factor: For most household tasks, a Phillips head works fine.
- Legacy: Once every factory in America calibrated for Phillips, switching became too expensive.
Real World Performance: Robertson vs. The Rest
If you walk into a Home Depot in Toronto, the screw aisle is dominated by square drives. In a Home Depot in Ohio? It’s a sea of Phillips and the occasional Torx.
📖 Related: Why sky blue plain hd wallpaper is the smartest thing you can put on your screen
Torx (the star shape) is the only real modern rival to the Robertson. It offers even more surface area for torque, but it has a major downside: cost. Stamping a star shape into a screw head is more wear-and-tear on the machinery than stamping a simple square. For high-end construction and decking, people are finally moving toward square or star drives because they’re tired of stripped heads.
Honestly, if you are doing a home renovation, stop buying Phillips wood screws. Just stop. You’re making your life harder for no reason.
The Loneliness of the Canadian Inventor
P.L. Robertson was a bit of an odd duck. He was known to be prickly. He lived in a hotel for much of his life and never married. His life was the factory. There’s a specific kind of tragedy in his story—he was right about the technology, but wrong about the business.
He died in 1951. He was wealthy, sure. His company was successful. But he never saw his invention become the global standard he knew it should be. The Robertson screwdriver remains a symbol of "what could have been" if a bit of ego hadn't gotten in the way of a great deal.
What You Should Actually Do With This Information
If you want to stop stripping screws and ruining your projects, you need to change your kit. It's not about being a tool snob; it's about mechanical advantage.
Upgrade your fastener game:
- Identify your needs: For furniture assembly, you’re often stuck with what’s in the box (usually Allen keys or Phillips). But for any project where you buy the hardware, go square-drive.
- Buy the right bits: A #2 Robertson bit (the yellow one) is the workhorse of the industry. Get a high-impact rated version.
- Color Coding: One of the best things Robertson did was color-code the handles. Green is #1, Black is #2, Red is #3. It makes grabbing the right tool from a messy bag effortless.
- Avoid the "Combo" Heads: You’ll see screws that have a cross and a square in the middle. These are the worst of both worlds. They don't fit either driver perfectly and strip out twice as fast.
The next time you’re frustrated because a screw head turned into a smooth, useless crater, remember P.L. Robertson. He solved this problem 120 years ago. You just have to use the tool he suffered for.
Actionable Next Steps
- Purge the junk: Go through your junk drawer and toss any driver bits that show signs of "rounding" or wear. A worn bit is a guarantee of a ruined project.
- Trial a box: On your next deck repair or framing job, buy one box of genuine square-drive screws instead of the standard Phillips. The difference in physical effort is immediate.
- Check the fit: When using a Robertson, ensure the bit seats fully. If there is paint or gunk in the hole, the taper won't engage, and you'll lose the primary benefit of the design.