vernier caliper spec "depleted"

[esteban]

Hi all, I'm a novice, and need to become knowledgeable about this particular area of PMEL:

I'm a PMEL customer, I have a 40" dial vernier with no mfgr ID; this tool was probably made in the 50s-70s, we've been using it for decades.     PMEL recently told us they can no longer calibrate it because AF METCAL is "depleting" the MIL spec part number it was identified by.   Can anyone tell me:

What type tools does this MIL spec affect?  (I'm not told what spec it is, probably it's something generic for this type tool?)
Why AFMETCAL is 'depleting' this MIL spec?
Can anyone see a way to salvage this otherwise perfectly servicable tool?

Thanks.

[ck454ss]

Lol gotta love Pmel.

I would just put a Limited Use on it with the accuracy calibrated to.

[esteban]

Thanks for your help - is limited use the same as limited calibration? 
PMEL responded that AFMETCAL is doing away with generic listings, such as MIL SPECs - can anyone tell me what MIL SPEC covered large dial calipers?

[StuG]

GGG-C-111.   I believe.

[michthai]

Your best bet is to look in GIDEP. Search under "vernier caliper" and you will find all the information you need.  You will find both AF and NAVAIR procedures there.

[TinkerPMEL]

The item can still be calibrated under the current AF guidelines using the generic WUC in K100-1.

[Colt45]

 Be careful about limited calibrations. I am a big proponent of limited calibrations when procedures expire, but you must know what you are using the tool for. Do you know what the tolerance is of the measurement you are performing?

What jaws are you actually using on this, inside or outside?

It does not require much to calibrate a caliper of this size, but as far as technique goes, it is a major pain in the but.

Accurate measurement requires perfect perpendicularly.

Who makes the caliper?

I am not Air force, but 90% certain current procedures allow for full calibration.

[jeroboambramblejam]

Probably a typo for 'deleted';  as for cal, if it's within one minor increment, that's all one can reasonably expect from a tool~

[jimmyc]

one minor division is probably over specced for a 40" dial.  the 0-6" is one md and the spec at 12" is  usually 1 1/2 (2 md)  starrett 120 spec Accuracy (in) 0-6" (+/-.001") 6-12" (+/-.0015")