- Jul 14, 2017
I don't come across many examples of manufacturing defects in fasteners, certainly not enough to be considered significant.Over the years i've seen lots of defective hardware, under sized, over sized, cross threaded, but this is a first for me, how come the whole batch passed QC, around 500 pcs almost all split in half, has anyone come across this with stainless steel bolts.
I did exchanged them, but the thought of what can happen if i did not catch them is bothering me, the supplier is not at fault is the manufacturer. Yeah they are M8x25mm, everything here is metric.I don't come across many examples of manufacturing defects in fasteners, certainly not enough to be considered significant.
What you pictured is new to me.
Rather than asking "how come the whole batch passed QC", I'd just return them and look for a more reliable supplier.
Are those metric fasteners, supposed to conform to some DIN or other standard?
I don't know how your supply chain works in Macedonia but, assuming that you didn't specify the manufacturer, I would certainly consider the supplier (seller) responsible for dealing exclusively with reputable manufacturers and buying fasteners that conform to applicable standards.I did exchanged them, but the thought of what can happen if i did not catch them is bothering me, the supplier is not at fault is the manufacturer. Yeah they are M8x25mm, everything here is metric.
RJ, i think you're are right, this must be cold shutdown or double feed.With large manufacturing lots, quality control is exercised by random sampling. The frequency of sampling is determined in part by previous history. As the number of incidents of bad parts decreases, the sampling becomes more lax. Modern quality control relies heavily on statistics.
My guess is that the defect arose because of a bad stretch in the stainless steel coil used to make the bolts. Most likely, this was caused by a cold shut in the rod forming process which could go unnoticed by the rod manufacturer. When the rod was converted into bolts, the bad section resulted in a number of bolts in the batch with the defect. These could easily be missed by the quality control sampling.
Bringing this up to the vendor should result in the filing of a non-conformance report to the bolt manufacture who, in theory, will take up correctove actions including increased sampling rates and determining the root cause of the problem.
If it points to the rod manufacturer, they will go through the same process..
Indeed it is, however a majority of consumers will not pay more for increased inspection intervals or very expensive in-process inspection technology.Harrumpf. Even at 1,000 pieces/hour, that's still a half-hour's worth of 100% bad parts. It's pretty poor manufacturing to not notice that.
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