Standard for Micrometer Anvil Flatness

[WindedAlpaca]

Hi there, I hope someone can help me... our Global Quality manager wants to update our Calibration acceptance criteria to the DoD standard; this would change our current .0005" Flatness to .00005".

We are training to find standards that support our argument that this change is necessary and the cost isn't justified for something our customers don't require.

Anyone know of the commonly accepted standard for Oil and Gas? Or just standards that cover this in general? (I am having trouble getting a copy of the NIST standard ) I am particularly interested in what the standard is for High-Precision industries, like Aerospace and Laboratory/Medical equipment.

I appreciate the help on this!!!

 

[Eredhel]

Are you a calibration lab?

 

[WindedAlpaca]

No, we are a doing internal calibration of shop gauges.

 

[howste]

My opinion is that the equipment should have flatness appropriate to the tolerances being measured, and there's no point in going to stricter tolerances unless it will have an impact on the measurement results.

I can't point you to a standard that says that though. IMO the fact that there is no de facto standard for this tells me that the tolerance should depend on the application. If the tightest tolerance that you measure is ±0.005, would it make a difference if the flatness was 0.00005 vs. 0.0005?

 

[joed152p]

What does the manufacturer say about the flatness? Also if you have a tolerance of +/- .005 why add the burden of placing .00005 tol on mic anvil flatness???

 

[Eredhel]

I don't know of a specific standard that could be used to push back. If it's out there I'd like to know too. But it definitely seems excessive. What DoD standard is he referencing?