Re: Gage pin calibration procedure
The national standard for calibration of plug gages is the following:
ASME B89.1.5-1998
Sections 4.5.1, 4.8, 6.1, 6.2, Table 3
Note that two of the above sections talk about calibration by a noncontact method (ie laser micrometer) and the other talks about the method you would use with a bench micrometer.
You can purchase this document from
www.asme.org.
Note that table 3 gives the specifiction for different calsses of plug gages. There is another paragraph that talks about plug gages that are class ZZ which is most likely what you have since you referred to them as "pin gages" .
In general, when people talk about pin gages, they are talking about the sets which are mostly class zz thiough class z are getting to be more popular.
Table 3 gives you all of the specifications based upon class.
For class zz pins tolerance is typicall +0/-0.0002" or +0.0002"/-0.
Wether you need a bench mic ior not depends on your needs for accuracy. If you sent these to me (which you could do since I am in Cleveland as well), I would use a laser micrometer whose accuray is +/- 30uin and the calibration would have a total uncertainty of about +/-70uin. If you required better accuracy, I would use somehting different to getthe uncertainty down to about 7uin (you can get 10 times the accuracy for about 5 times the cost). Note that if I didn't have the laser micrometer, I would use a bench micrometer for ZZ pins.
At a minimum, you should use about 4:1, so if the accuracy of the pins is 200uin, you should use an instrument accurate to about 50uin. Don't confuse the accuracy of the gage you might use with the resolution orf that gage. You can get a digital micrometer to show this many digits, but it really is not that accurate.
I hope this helps some.