Bolt Pitch

[Dominik]

M14 x 1.5 mm or M14 x 2.0 mm. There is no 150 or 200 pitch.

The pitch (distance from one root, or tip) between treads is 1.5 mm or 2.0 mm.
The diameter of the bolt is 14 mm.

Note: The 1.5 mm pitch has a root diameter of 12.5 mm. If you ever like to tap a M14 x 1.5 into a hole, drill 12.5 mm. And, who guessed it: The 2.0 mm pitch has a 12 mm root diameter.

You cannot tap the one into the other. That's like tapping a 3/8 UNF into a 3/8 x 13 UNC bore.

Interesting trivia:
A M12 x 1.25 mm bolt fits into a 1/2" x 20 UNF (or 1/2" x 20 UNF nut onto a M12 x 1.25 mm stud). BUT will NOT give a tight fit - obviously. Happens with wheel or cylinder head fasteners.

Last one:
3/8" x 24 UNF brake line fitting screws down M10 x 1 mm metric equivalent. Will never seal!