Help me...american metric system drives me nuts...

Triumph

Lifer
Oct 9, 1999
15,031
14
81
First problem - there's no such thing as the "American metric system."

1 inch = 2.54 centimeters. Or for wagging it, 1 inch = 25 mm. Good enough.
 

So

Lifer
Jul 2, 2001
25,923
17
81
I assume the american connection infot is not given as 1/2, it's given as 1/2"

Just FYI: in the american measurement system, the double tick mark aka "quote" (") denotes inches while the single tick mark (single quote) (') denotes feet.

So

1/2" == .5 inches ~= 12mm

1/2' == .5 feet == 6 inches == 144mm