UNC Machine screws
UNC ... Unified National Coarse
This is an american thread, which was 'borrowed' after WWI by the british.
The hexagon socket screws on this page are stainless steel of A2 or A4 quality.
UNC thread (coarse thread) is used in materials like Aluminium, Zinc-Casting.
Beside all the usual screws with slot and phillips drive or pozidrive there are also screws with hex allen haed with UNC thread available. In german language these screws are calles INBUS. How this name became commen, just have a look here: http://de.wikipedia.org/wiki/Inbus
Please find some further interesting links here: 'LINKS