I worked on a light sport aircraft imported from Eastern Europe that was held together with a lot of metric cap screws instead of hex bolts. These wanted to be torqued to similar values that AN Standard Steel bolts wanted for their size but the drive is 5 times smaller, so it tended to be the point of failure. Worked out okay I guess because the head would round out instead of ruining the threads so you could usually get a pair of vice grips on the head to remove the bolt.
Hex, especially in lower quality fasteners, has a tendency to round out.
Fair point. I’ve never had one round out, but I see how the low contact area and flat angles could do that.
I worked on a light sport aircraft imported from Eastern Europe that was held together with a lot of metric cap screws instead of hex bolts. These wanted to be torqued to similar values that AN Standard Steel bolts wanted for their size but the drive is 5 times smaller, so it tended to be the point of failure. Worked out okay I guess because the head would round out instead of ruining the threads so you could usually get a pair of vice grips on the head to remove the bolt.