Comment by yason

And why the heck do sockets and drives come in negative powers of 2 such as 1/2", 1/4", 1/8" whereas smaller tolerances come in 1/1000's of an inch? Why not 1/512" and 1/1024" ? This gets into awkward conversions even within the imperial units such as 5/8" into decimal 0.625" instead of something like 640/1024" because of no good reason :-/