One of the characteristics of stainless steel that is different from other steel materials is its good use surface, especially cold-rolled stainless steel, which is widely used in surface decoration materials or various types of household appliances and appliance shells with decorative effects. Therefore, scratches are a serious defect. Once more serious scratches appear on the surface, the material may be directly scrapped. The quality objections to scratches are also the most common in the stainless steel industry. The quality objections to scratches in this series hope to provide some reference to customers engaged in the sale, processing and application of stainless steel. 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 a fixed-length 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 stainless steel processing, minor scratches are difficult to avoid, and the lower surface is not easy to check, so it is difficult to ensure the yield required by the customer. In fact, similar to the scratches proposed by the customer, it is difficult to avoid. If the surface of stainless steel rubs against a hard object, similar scratches will occur. If you do not feel when you scratch with your nails, the general surface frosting and 8K can be eliminated. 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 standards and the 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.