I have stacks of these sat in the pile of random HP bits in the corner of the server room.
Their purpose......
If you ever need to recocate your server racks and are not going to unload all the servers first you are supposed to put these screws in.
HP also use them if they ship you a rack with the servers preinstalled - hence the remove after shipping
Although you than end up taking all the kit out again when it arrives anyhow as either: 1 the server are not positioned in the rack U's you wanted them or 2 the rack doesent fit through the doors of your building, being about 2 cm taller than a standard door frame (good design that!)