How to identify the standard of scratches/Customers purchase 0.4mm stainless steel flat plates to make housings for household appliances. After using them for a period of time, they submit quality objections to suppliers, saying that the scrap rate due to scratches on the surface is too high. After inspection, the scratches mentioned by the customer are basically slight scratches, the length is less than 5mm, no feel, irregular distribution, and are not continuous, and the randomness is relatively strong. It can be judged that the part is randomly generated during the processing. The raw materials are inherent, and because they are very slight, they are generally not found during processing. The customer uses an indefinite scale board, which needs to be slit and flattened. The customer requires no paper padding, and the bottom surface must be free of any scratches. After multiple passes of processing in stainless steel enterprises, slight scratches are difficult to avoid, and the lower surface is not easy to check, so it is difficult to ensure the yield required by customers. In fact, it is difficult to avoid scratches similar to those proposed by customers. If the stainless steel surface rubs against a harder object, similar scratches will occur. If you do not feel when you scratch with your nails, the surface is generally matte, 8K, etc. It can be eliminated after the surface treatment process. Because the customer only mentioned no scratches when reaching the purchase agreement, and the processing center's explanation of scratches refers to the scratches, and the scratches are difficult to avoid. The two sides disputed whether the defect was scratched. Finally, the two sides re-enacted the standard and number of scratches, and detailed regulations on the depth and location of scratches and the scrap rate due to scratches. Since there is currently no standard that specifies the stainless steel surface in great detail, the standard when customers purchase stainless steel is often different from the supplier. A simple "no scratch on the surface" is difficult to achieve a real standard. If you have high requirements on the surface, you may wish to sit down and negotiate some detailed regulations to avoid objections.