Certain things like bikes, cars, and furniture use hexagonal bolts for fastening. Hex bolts can only be used with the right diameter key and they don’t slip like Phillips and Flatheads. Also, the hexagonal tip keeps bolts from falling so you don’t need a magnet to hold your fasteners. Furthermore, it’s easy to identify which Allen key you need for each fastener, and you can use ballpoint hex keys if you need to work at an angle.
Since the hex bolt design is so practical, why don’t we use this type of fastener for everything? Why don’t we see hex wood screws and hex drywall screws ?
Edit : I’m asking about fasteners in general (like screws, bolts, etc)
In: Engineering
The Robertson head is the best overall screw head.
NOT that awful American square head with the lack of taper and crappy fit.
The tapered square hole Robertson has excellent contact area between driver and screw, lots of forgiveness with size tolerance for both the driver and fastener as long as you get the taper correct, and only 5 sizes of driver to go from very large to very small fasteners. In practice, only three sizes (Red, Green and occasionally Yellow) cover just about every likely scenario. Screws rarely strip, because the tool force on the screw is well distributed over the screw’s entire hole.
The screw is securely held by the driver in almost any orientation, and if the driver is slightly magnetic, those screws never fall off.
But back in the day, the inventor was just a bit too greedy, so US manufacturers introduced a square drive *without* that critical taper (to avoid patent issues) resulting in a shitty combination that results in stripped screwheads and pissed off users. The square drive completely spoiled the market for the much better Robertson.
In Canada, the construction and electrical industry is quite dominated by Robertson applications, but it never caught on in the states.
Every time I have to drive a Phillips or slot screw, I fervently wish that the damn thing was a Robertson.
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