metric verses standard machine screws

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
First observation in a black machine screw that could be either metric or standard (and not country of origion of the fixture,) what is the most observible difference between a black domestic or metric screw in often making it easy to tell the difference? Is this a common trait no matter if black or zinc/natural?
 

gafftapegreenia

CBMod
CB Mods
Joined
Sep 24, 2005
Location
Michigan
Shot in the dark: Spacing of the threads?