measuring a needle?



I whas wondering if there is a tool or a way to measuring the thickness of a needle.I have recieved a L Fischer by letraset , i know its an oldie but it comes standerd with 5 nozzels tips and needle,s,
So if someone has any idea to find out the thickness it would be great.

Immortal Concepts

I know this is a really really old post but still beneficial knowledge for some. Most needles if you look at the back of them have a ring cut into them. 1 ring is .2mm 2 ring is .3 etc. Some of the really old ones actually have the number stamped on the back, just extremely hard to see. Same goes for the crown caps. Only the nozzles don't have markings but it's pretty easy to compare.


Air-Valve Autobot!
Why measure the needle?

The OD of the needle won't have a lot to do with the tip size..The OD of the needle is a concern when it comes to the body seals, not so much what its designed to spray, thats what the angles and such at the tips all about..But yer a vernier or micrometer if ya wanna be real accurate will measure it for ya..(If of course you know how to read one) but as someone mentioned, if ya got a gun with multiple needles and head assembly's there shld be some kind of identifying mark as to which one goes with which...