I would like to know if it is possible to reduce a drill bit diameter (the body and not the shank). From times to times I need to work with dimensions that are not integer number or half number.... example: where I live I can only find drill bits 6mm or 6.5mm or 7mm..... however, in some cases I really need to have a dimension of 6.25mm.

Is this even possible to do, if yes how?