I rejected plastic parts that contain two distinct gouges/grooves that are obvious defects, and are not depicted on the print, but for which our vendor claims are acceptable because, despite these defects, the part is within tolerance; meaning even accounting for the depth of the gouges, they remain dimensionally within conformance. Of course, I did not reject the parts for this reason (dimensional non-conformance), I rejected them for containing a feature (or defects) not depicted on the print.

When I worked at a plastic injection molding manufacturing company, we called this defect ‘mold mark’ because it represents either a physical anomaly on the surface of the mold or a mark caused by the ejection of the part from the mold during the manufacturing process.

I have been asked to obtain an industry standard of some type to use as an indictment when replying back to the supplier. The print itself cites ASME Y14.5M-1994, which is a standard that addresses interpreting dimensions and tolerances only and I beleive would not apply to the reason I rejected the part.

I need to find a standard that says when a part contains features not depicted on the print, it is non-conforming. Seems pretty obvious, I know, but that appears to be what I am looking for.

Can anyone help? Thanks.

MICHAEL

Sounds like your supplier is grabbing at straws. If it's an obvious defect, they should take responsibility.

An alternative is to just accept their response - then ask accounts payable to pay for the parts with a check with "extra features". Such as the word VOID printed across the face of it. Maybe then they will understand. :notme:

I rejected plastic parts that contain two distinct gouges/grooves that are obvious defects, and are not depicted on the print, but for which our vendor claims are acceptable because, despite these defects, the part is within tolerance; meaning even accounting for the depth of the gouges, they remain dimensionally within conformance. Of course, I did not reject the parts for this reason (dimensional non-conformance), I rejected them for containing a feature (or defects) not depicted on the print.

When I worked at a plastic injection molding manufacturing company, we called this defect ‘mold mark’ because it represents either a physical anomaly on the surface of the mold or a mark caused by the ejection of the part from the mold during the manufacturing process.

I have been asked to obtain an industry standard of some type to use as an indictment when replying back to the supplier. The print itself cites ASME Y14.5M-1994, which is a standard that addresses interpreting dimensions and tolerances only and I beleive would not apply to the reason I rejected the part.

I need to find a standard that says when a part contains features not depicted on the print, it is non-conforming. Seems pretty obvious, I know, but that appears to be what I am looking for.

Can anyone help? Thanks.

MICHAEL

Before any standard has any weight wrt rejection criteria, both parties must have agreed to it in advance. Even if you do find some workmanship standard that addresses your situation, it's not going to be binding on your supplier. How far you'll get with this supplier is dependent on a number of factors, such has the amount of work they do for you (in $) and how important new business from you might be. In my experience, suppliers who take this sort of tack are sending a message that says, "We'd rather lose your business than eat these parts."

Your only recourse at this point is to make it clear to the supplier that the parts are unacceptable and that they'll get no further business from your company if the matter isn't taken care of to your satisfaction. You might also want to explicitly state surface finish requirements on your drawings, but be careful not to make them more stringent than they need to be.

Before any standard has any weight wrt rejection criteria, both parties must have agreed to it in advance. Even if you do find some workmanship standard that addresses your situation, it's not going to be binding on your supplier. How far you'll get with this supplier is dependent on a number of factors, such has the amount of work they do for you (in $) and how important new business from you might be. In my experience, suppliers who take this sort of tack are sending a message that says, "We'd rather lose your business than eat these parts."

Your only recourse at this point is to make it clear to the supplier that the parts are unacceptable and that they'll get no further business from your company if the matter isn't taken care of to your satisfaction. You might also want to explicitly state surface finish requirements on your drawings, but be careful not to make them more stringent than they need to be.

I agree. What acceptance criteria is being worked to here? That is the obvious choice for quoting as it will determine the acceptable size of defects regardless of drawing tolerances.

Myself, I would start looking for a new supplier. In todays economy there are many suppliers who will go the extra step to attain and keep business. Your supplier doesn't seem to be one of them. I look at our suppliers as part of our company. if they are not interested in our sucess then I will "hire" new suppliers.

Doug

I don't think you are going to find a standard that applies to your situation. As others have said, a reasonable surface finish call out on your prints is probably a good idea for the future. Meanwhile, I would dump the supplier, change the print, and move on.