Spyderco Vallotton Detent

[inactiveingredient]

My spyderco vallotton which i had been using for three months has worn out the detent ball. It's worn down to the point where only about .5mm of the ball is left sticking out the lockbar.
Ive been considering knocking it out to replace it with a ceramic ball.
I do not have any way of measuring the diameter of the original detent ball and i was wondering if anyone knew the size.

 

[nccole]

Harbor freight has digital calipers for $10. For what you are doing that should be good enough.