Pit bag: possible material itself and crush injury; Pitting: either oil pollution or the material itself; Scratch: the product is not fully protected during transmission or transportation, or the material itself; Brush machine: material problem; Drawn side wall is not straight and wrinkled: material or mold, or not oiled; Big burr: edge drop: does it mean lack of material? The material itself, the mold positioning is loose, and the remaining material; Impact speed, material and mold height; Hole deformation, punching speed, dull needle not sharp, poor mold height; Flanging warping, flanging/bending not in place, trimming line/flanging/bending line deviation, flanging height mismatch, forming (stretching)/shaping not in place: die or machine adjustment problems.

PS: I don't understand coughing and necking for the time being. I hope it helps.