We often encounter customers requesting electroplatin […]
We often encounter customers requesting electroplating on the surface of the screws. Do you know the thickness of the electroplating layer of the screws? Today, the bolt factory - Weigao Standard Parts will explain the plating thickness of the screws for you.
Due to the uneven distribution of the thickness of the screw plating layer, the standard quotes four definitions of the plating thickness, namely "nominal plating thickness", "batch average thickness", "local thickness" and "effective plating thickness". "Nominal plating thickness" refers to the nominal plating thickness of threaded fasteners, and cannot represent the actual plating thickness. The actual coating thickness of screw stainless steel fasteners is described by "effective coating thickness". "Effective coating thickness" includes two aspects of "batch average thickness" and "local thickness". The thickness of the plating layer of the screw thread cannot be represented by the plating thickness of a part. Regardless of the screw thread processed by rack plating or barrel plating process, each part in the same batch of parts cannot reach the same plating thickness, but the change in screw thickness is Obeying the normal distribution, we assume that the coating thickness is evenly distributed on the surface of the screw to calculate the average thickness of the screw coating. This leads to the concept of "batch average thickness", which can be used to describe the entire batch of threaded stainless steel. The plating thickness of the fastener. The "batch average thickness" in standard table 1 is a range to indicate. The average thickness of the minimum batch of screws is to ensure the anti-corrosion requirements of the threaded fasteners, and the average thickness of the maximum batch is to ensure the screwability of the screw fasteners after plating.
"Local thickness" in the standard actually refers to the minimum local thickness. The minimum local thickness of a screw describes the minimum specified value of the plating thickness that the screw fastener should reach on the specified local test surface. The data verified by the screw test show that the local coating thickness values measured on the screw, bolt head and screw, stainless steel bolt, screw screwing surface, these specified local test surfaces are greater than the average thickness of the batch. The average thickness value meets the requirements, and the minimum local thickness can also meet the requirements. The screw test results also confirmed that the numerical relationship of "nominal plating thickness", "batch average thickness" and "local thickness" is correct, which constitutes the theoretical basis for the detection and acceptance of the plating thickness of threaded stainless steel fasteners.