Want to process a high quality product, we must look at your processing methods, and processing materials, and processing equipment, whether the appropriate processing, these are a great reason, non-standard parts processing is not only, then how to produce and process high-quality non-standard parts.
In order to process a qualified part, the thickness of the layer of metal that must be cut from the blank, known as the machining margin. Machining margin can be divided into process margin and total margin. The thickness of the layer of metal that needs to be removed in a process is called the machining allowance of the process. The total amount of metal that needs to be removed from the blank to the scrap is called the total margin, which is equal to the sum of the margins of each process for the corresponding appearance.
The purpose of leaving machining allowance on the workpiece is to remove the machining errors and appearance defects left by the previous process, such as cold hard layer, porosity, sand trap layer on the appearance of castings, oxide skin, decarburization layer, cracks on the appearance of forgings, internal stress layer and appearance roughness after cutting. So as to improve the accuracy and appearance roughness of the workpiece.
The size of the machining allowance has a large impact on the processing quality and consumption efficiency. The machining allowance is too large, not only increases the amount of machining labor, reducing the consumption rate, and increases the material, tools and power consumption, and improve the processing costs. If the machining allowance is too small, it can not eliminate the various defects and errors in the previous process, but also can not compensate for the clamping errors in the processing of the process, the formation of scrap. The selection criterion is to ensure the quality of the premise, so that the margin as small as possible. Generally speaking, the more the finishing process, the smaller the process margin.