cosmetic specifications to indicate a acceptable level of defects

[rmetzger]

Does anyone know of a cosmetic specification for part surfaces that indicates acceptable levels of defects (scratches, digs...) for non-optical parts. We have a few parts that we are looking for a uniform exterior surface finish allowing a level of imperfections. I've found a number of company specific guidelines / specifications but have not found anything universal (ASME, MIL, ...)

For our application, the metal surfaces are being sanded or ground to create a uniform finish but occasionally we get in parts with a few scratches. Our QA is rejecting parts that are not perfect so we'd like to give the suppliers some room to get the parts to an acceptable level of quality without requiring perfection. We can create our own standard but if there is already one in existence I'd prefer to reference it.

 

[AndrewTT]

ASME Y14.5 - 2009
"1.8.21 Surface Texture - Methods of specifying surface texture requirements are covered in ASME Y14.36M. For additional information, see ASME B46.1."
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ISO Geomterical Toleranceing, Krulikowski
"Surface imperfection is different from surface texture. Surface texture defines requirements for surface parameters (i.e. waviness, form, etc.) that are on the micro level (micrometers). Surface imperfection defines requirements for the surface irregularities that are on the macro level (millimeters). These surface imperfections are deviations permitted by the indicated form tolerance, but excluded (filtered out) during the inspection of surface texture."

ISO standard on surface texture - ISO 1302:2002

ISO standard on surface imperfections - ISO 8757:1998 (this standard is not specified on the drawing, it is invoked by specifying ISO 1302:2002)
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I have never read any of these standards on surface texture/imperfections. This is as much as I can help.