Robertson Head Screw (Square Drive Screw)

[Jim Bennett]

Originally Posted by Carl V

Because they can "cam out", which is exactly why I try to avoid them for any other uses!

That makes perfect sense. So obvious, I missed it.

[Carol H]

Originally Posted by Carl V

Also, here in francophone Quebec, they are not usually called by the Robertson name. Although most people would know what a Robertson screwdriver is, people just call them "square screwdrivers".

Which explains why sometimes we see the designation of SQ on some of the packaging here in Canada. I wondered were that came from!

[Harvey]

I really like the Robertson screw system (liked the clutch head also when they were being commonly used). From many years of working on guns (& other precision type equipment) I've become pretty particular about using the correct screwdriver for single slot screws. It's very important to use the correct size driver, not only width of the blade but thickness also, that fits the screw slot exactly. 'Gunsmith' drivers are hollow ground & the blade is same width/thickness wherever it contacts the screw. Also 'generic' common screws may not have a 'square' bottom in the slot, which can also promote slippage. I've seen so many 'boogered' slots in screw heads even on construction type work where precision/looks may not be important. Besides, it's much easier to use even a slotted screw when you have the correct size driver. Not hard to identify a 'Bubba' job from all the damaged screw heads. I've also come to appreciate the 'Torx' head screws over the past few years. They don't 'hold' on to the driver as well as Robertson but they do 'drive' nicely...

[Gordon in Idaho]

Commonly known as a "Yankee Screwdriver", these are still easy to find:
http://www.amazon.com/Eazypower-8196.../dp/B0009XHRUE
As a cabinetmaker, I switched to Robertson screws and bits many years ago. My supplier was McFeely's (Screws & Fasteners), and I think they're in New Jersey.
Now...does anyone know what Pozidrive screws are (without Google)?

[redbarron55]

Yes

Sent from my SCH-I605 using Fiberglass RV mobile app

[peatle]

Lee Valley actually carry a screw with a 'Recex' head which can be driven by either a 'Robbie' driver or a 'Phillips'.

I came to Canada in 1970 and soon discovered the ease of application of the Robertson Screw ( patented approx 1904 ) compared to the slot and Phillips head screws that I had used during my apprenticeship as a Carpenter and Joiner in England.

I was amazed that I could place a Robertson head screw on the end of the screwdriver and put it to the piece of work without it falling off. Never looked back and, more often than not, anything other than Robbies that came with something to install got tossed in favour of some Robertson screws from my stock.