Cap Screws and Allen Keys

Please try do some research first.

Hex key - Wikipedia, the free encyclopedia

No, that's not true. Why don't you tell us what you're looking for and maybe we can help. But, cripes, I've got a standard book of fasteners that must have 400 plus pages. I can't summarize everything.

Let us have a bet Even those 400 pages will not have all types of fasteners and their grades.

had the OP asked for aal types of steels with their mechanical and chemical properties, it would have been just a bit easier.

The OP is confused between cap screw and soc hd screws.

As I recall, "Machinery's Handbook" (whatever the current edition is) gives an explanation about various types of bolts and screws. They are not exactly the same, and part of the matter involves historical usage of the terms.

Roughly speaking (there may be exceptions), bolts and studs are used with nuts. Screws go through one piece of material and fasten into a second piece of material by either a tapped or self-tapped hole; except in the case of set or jack screws, it is the first material that is tapped, and the set/jack screw presses onto or into the material behind.

Unfortunately, everyday usage of these terms is often imprecise, resulting in confusion.

There are too many types of either for anyone to be able easily to list all of them.