"Puckdropper" wrote in message
If you're manufacturing or building something, stick to the most common
sizes. For wrenches, that's 3/8", 7/16", 1/2", 9/16", and 5/8". Sizes
such as 15/32" are sometimes found in socket sets, so if you want to use
that size make it socket accessible.

A good reason to use metric.