Machining margin of hardware parts

Machining margin of hardware parts

According to hardware parts processing manufacturers, in order to process qualified parts, the thickness of the layer of metal that must be cut from the blank is called the machining allowance. Machining allowance can be divided into process allowance and total allowance. The thickness of the metal layer that needs to be removed in a certain process is called the machining allowance of the process. The total margin that needs to be removed from the blank to the finished product is called the total margin, which is equal to the sum of the margins of each process on the corresponding surface.

The purpose of leaving a machining allowance on the workpiece is to remove the machining errors and surface defects left by the previous process, such as the chilled layer, pores, sand layer on the surface of the casting, and the oxide scale, decarburized layer, and surface cracks on the surface of the forging. , The internal stress layer and surface roughness after cutting. Thereby improving the accuracy and surface roughness of the workpiece.

According to the analysis of the hardware parts processing company, the size of the machining allowance of the hardware machinery parts has a great influence on the processing quality and production efficiency. Excessive machining allowance not only increases the labor of mechanical processing, reduces productivity, but also increases the consumption of materials, tools and power, and increases the processing cost. If the machining allowance is too small, the defects and errors of the previous process cannot be eliminated, and the clamping errors during the processing of this process cannot be compensated, resulting in waste products.

The selection principle is to make the margin as small as possible under the premise of ensuring quality. Generally speaking, the more finishing, the smaller the process margin.