ink pen calipur

[Frank S]

Sometimes you find a useful tool that is nothing more than a promotional give way.
I've had this pen for probably 10 years now it's come up MIA several times but somehow I always seem to relocate it
I've used it thousands of times to measure the ID or OD of something in a scrap yard when I have forgotten to carry along a real caliper
Funny thing is it will produce a surprisingly close reference the ID is a direct reading for the OD I simply add 4 mm to the reading I can usually tell within .5 mm a and if I put my glasses on I can get that to .2 mm but normally I am just interested in the nearest whole MM


I got it at a trade show handed out by the Fischer fastener company. I think that I'm on about the 3rd refill now from doner pens