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
Hex head screws do slip, just less than Philips/flat but more than Torx or possibly Pozidriv (I don’t have much firsthand experience with Pozidrive). [This site has a nice illustration](https://rtstools.com/why-torx-bolts-are-better-than-hex-bolts/) of how torque is applied on Torx fasteners vs hex which allows for more even pressure distribution. Basically hex heads apply most of the force to the points and not the flats of the fastener so they’re less efficient compared to Torx.
Hex also has the hitch that there are both SAE and metric sizes so you effectively need two sets of bits/wrenches if they were in more widespread use. At least with bikes and Ikea they’re always metric or at least have been in my experience.
In general I’m guessing you don’t see hex as much because if Philips heads won’t suffice manufacturers just go right to Torx and skip over hex which would sit in the middle.
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