# Adjusting Nsk Outside Micrometer



## Splat (Jul 30, 2016)

I have an old 1" NSK micrometer, model AB02, that was my father's. It's in excellent condition but it's off by -0.0025. I have no tooling with it so I don't know how to adjust it. There is a very small hole in the backside of the sleeve. Inside that small hole I can see metal but not slotted or anything, so I guess that's the backside of the sleeve. I'd post pics if I could find my cable for the phone. How can I zero this mic? Thanks.


----------



## Tony Wells (Jul 30, 2016)

Usually you just use a spanner to turn the sleeve to align the zero with the datum, but 0.0025 is a bit more than generally seen. On some mics, and I can't remember if NSK is built this way, the thimble is mounted on a taper, held on by a screw through the friction or ratchet drive. Once you remove the screw you can tap gently on the side and dismount the thimble. Then remount it as close as possible and make the final adjustment with the spanner in the sleeve.


----------



## francist (Jul 30, 2016)

I suspect my NSK may be newer than the OP's, but for what it's worth here's what my instruction pamphlet says:

-frank


----------



## Splat (Aug 1, 2016)

Thank you Frank!  I'll check this out tomorrow and let you know. Hope I don't break it!


----------

