Shenzhen Shi Shi Tong Metal Products Co., Ltd

  What is the impact on the quality of the fine thread self tapping screws head? The quality of a product is affected by many factors, but the reason for the problem is different for each different component. Usually, we can’t say that it is directly determined that it is a factor affecting the quality, even if it is a small screw. The quality of the screw head and the thread are different. So let’s take a look at the reasons that affect the quality of the  fine thread self tapping screws  head. The head of the  fine thread self tapping screws  is not round. The reason is that the selection of the die of the screw die is not proper or the punching is not full enough. The screws have burrs or burrs. The reason is that the die is poorly formed, mainly because the gap between the punch and the die hole is too large or the punch is too short. The head of the  fine thread self tapping screws  is smashed. The reason is that the installation of the screw mold...

The inspection of the  fine thread self tapping screws  generally has two types: destructive inspection and non-destructive inspection. Non-destructive inspection: Randomly take samples from the acceptance batch according to the requirements in the table, perform visual inspection or other non-destructive inspection, such as using magnetic technology or eddy current. If the defective sample is found not to exceed the permissible limit, the batch is accepted. If the number of defective samples is found to exceed the allowable limit, the destructive inspection is performed in batches with these defective products. Sample size for visual and non-destructive inspection Batch (N)Sample size (n) N≤120020 1201≤N≤1000032 10001≤N≤3500050 35001≤N≤15000080 Note: 1. Batch refers to the same type, specification and performance level, and the number of  fine thread self tapping screws  submitted for acceptance at the same time. The sample size is based on the in...