What you want is spring loaded ID Calipers. Photo attached

• http://files.engineering.com/getfile.aspx?folder=7e1c93ae-8518-4e98-ab98-7b

Do you want to measure it or inspect it?

A telescopic bore gauge would allow you to measure with a mic but probably not the best for a 0.0006" limit, a CMM would work fine but obviously not cheap.

If you just want to inspect could you not get a go-nogo gauge made on upper and lower limits but only say .500 wide so it could be fed through the "hole".
 

rustbuster,

That gage doesn't look to be accurate enough, as I'd have to measure the distance across the points after removal.

ajack1,
I'm inspecting the bore (well, I think I am anyways) for serviceability to check for wear, etc...

We do have a few CMM's, the only problem being that the bushing is installed in another part, resulting in a pretty complex geometry, i'll check with the CMM programmer though.  Also the go-no go sounds like a good thing to look into.

I've got a few paths to look down now, thanks!

Here is another option but not sure you will get the accuracy you are looking for.

• http://www.machine-dro.co.uk/index.php?target=products&product_id=85

I can't see the picture by rustbuster so excuse me if this is a duplicate.
I would give Dyer a call and get their catalogue along with their recommendations. Their website is a little hard to navigate.

http://www.dyergage.com/index.htm


You can use a gage similar to this or better yet add a couple of carbide balls to the points. I can;t gave you a better idea as my old catalogue numbers don't match.

http://dyergage.thomasnet.com/item/all-categories/101-series-direct-reading-o-ring-groove-gages/101-100?&plpver=10&origin=keyword&;filter=&by=prod

That is more or less what I linked to Unclesyd.

However it remains debatable of something that measures to .0005" or .00039" in my case would be accurate enough to measure a limit of .0006".
 

ajack3, Yes they are very similar and probably like the one's posted by rustbuster.  

I know that Dyer makes comparator gages which have a narrower range with 0.0005" graduations and therefore can be interpreted to 0.00025" .  
It gets real tricky when you start to measure plus/minus 0.0005 on a worn or non uniform surface.  

To get more precision than afforded by gages from Dyer and others you will have to go to companies like Hanlo.

http://www.hanlogages.com/index.htm

cjohson0,

How much wear can you have and not be problem?
   If say it's 0.0001" you could have a special gage made that act as a go/no-go gage.

Where have you seen the wear on the part?

Mueler Gages

http://www.mueller-gages.com/