What does 6 x 20mm mean on a s***w or bolt?

Question

What does 6 x 20mm mean on a s***w or bolt?

Answer 1

it is 6mm in diameter and 20mm long.

Answer 2

6 is the gauge if the s***w and 20 mm is the lenght.

The guage is an imperial term which seems to have stuck

he smaller the guage the smaller the s***w etc On a bolt that would mean 6mm dia

Answer 3

I believe 6 = number of threads on s***w or bolt

mm=millimeter/metric

20 mm = 0.7874000000000001 inches

Answer 4

6mm thread with 20mm length

Probably metric too.