The cleanliness of the equipment used to fabricate these sheet metal components is not totally irrelevant in regards to use with processing a food product. For example, if the stamping/shearing equipment was previously used with a material containing a toxic metal like lead, beryllium, cadmium, etc. how would you ensure that all traces of these contaminants were removed from the sheet metal parts?
A good analogy is how recent regulation changes have required elimination of even trace amounts of beryllium from most aluminum castings. To comply with this requirement, aluminum foundries must use equipment that has never previously been used to process any aluminum containing beryllium. They must have documentation to prove this if they deliver castings for certain applications, like products being exported to the EU.