15mm wrench for 9/16 pedals?

Why is it that you need a 15 mm wrench for 9/16" threaded pedals? why not make it both sae of both metric?

Mike

Re: 15mm wrench for 9/16 pedals?

all fasteners on bikes are metric (everything you need a tool for)

the 9/16 is just the size of the hole that the spindle is going into, so it doesn’t matter if that is SAE