You rejected that part for THAT??
Rejecting parts for silly reasons complicates life for everyone.
Years ago, I dealt with a tricky machined part my employer bought for about $200 each. Most features had tight tolerances. This part got rejected for a minor issue: removing a burr from an outer edge. I checked the drawing, and the area needed a radius of about 0.005 inch. You could do this with a hand deburring tool. Using that tool to get precise measurements was very challenging. The deburring was more about looks than function.
They made the part from hard plastic. The deburring didn’t affect the form, fit, or function. The area that was out of tolerance was almost undetectable.
Critical dimensions matter, but this is absurd. If critical dimensions are wrong, the part won’t work as intended. Calling a deburring radius critical makes no sense.
What mattered was completing the deburring, not whether the radius was off. The goal was safety. It aimed to prevent workers from cutting themselves on sharp edges. Functionality was not the main focus. I’ve had success saying, “Remove all burrs and sharp edges,” rather than using a specific tolerance.
The inspectors aren’t to blame. They were doing their jobs. The issue lies with those who set the tolerances!
Years later, I met a former co-worker. We discussed how managers often reject parts for almost any reason (it makes them feel important!). My co-worker attended a meeting about a recent part build. One manager insisted on rejecting some parts. She showed a sample part and pointed out the so-called “flaw.” It was minor and hardly noticeable. The meeting ended without any action.
This same company faced similar behavior from a Japanese customer. The customer had a history of rejecting parts to get cost cuts. In this case, the part wasn’t the problem; it was the box that had a spot of uneven coloring! I don’t recall how someone resolved this “issue.” They sent a note. It said the box protected the part during shipping. Also, there were no specifications for this issue.
There are better ways to spend our time. Irritating vendors by rejecting usable parts won’t help build lasting relationships. The recycling facility likely couldn’t handle the material, so workers sent it to the landfill.
Norman T. Neher, P.E.
Analytical Engineering Services, Inc.
Elko New Market, MN
www.aesmn.org