Calibration for Solid Length Gauges

[Vadamalai]

? For measuring length below head in bolt blanks in as forged soft condition , we use thousnads of solid length gauges.These gauges are duly heat-treated to 45/48 HRC.The tolerance for the length in bolt blanks is 0.8 mm. These gauges are easy for verifying length for operators and there is no adjustment involved. Gauges are of ground finish and flatness is ensured.Conisdering the tolerance of the blank length,robustness of the solid gauges,extremely negligible chances of wear is periodic calibration is necessary for these?The Cpk in SPC of the bolt length is >2.
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Edited html error.

[This message has been edited by Marc Smith (edited 04 December 2000).]

 

[Al Dyer]

Is the gage used to qualify the part to customer specifications? If so, it needs to be calibrated at an appropriate frequency.

This can be determined based on the various statistical tools available. I.E. ongoing Cpk, PPM, Stability etc...

Looking forward to additional input!

ASD...

 

[Atul Khandekar]

From what you describe, it appears that these are Attribute gages (GO-NO GO). As such R&R should be done. If chances of wear as negligible, you may choose a suitable frequency for studies, like once a year or so.