What are the disadvantages of hex bolts?cylpro
Stainless steel and low carbon steel hex bolts . Any steel with a high yield strength can be used, but series 4xxx low carbon steel and series 4xx tempered martensitic steel are widely used.
they are higher profile than other types of fasteners. Also, the tools used to tighten them generally take up more room. They require either a wrench (needs a significant amount of space), or a socket (still can be tricky to fit in tight spaces). Lastly, any counterbored hole has to be massive relative to the fastener size, whereas something like a socket cap screw doesn’t require such a large counterbore.
Being that there are numerous grades, sizes and thread types/pitches I assume you want a generalized response. I can only say most hex bolts have a higher profile at the head when full threaded into place than most other hex bolts ….but they also come in low profile. It all depends on the application.