Precision machining is a process of altering the shape, dimensions, or properties of a workpiece using machining machinery. Based on the temperature state of the workpiece being machined, it can be divided into cold working and hot working. Cold working generally involves machining at room temperature without causing chemical or phase changes in the workpiece.
Hot working generally involves machining at temperatures above or below room temperature, directly causing chemical or phase changes in the workpiece. Cold working can be further divided into cutting and pressure processing based on the processing method. Common hot working methods include heat treatment, forging, casting, and welding. Firstly, there are requirements for material hardness. In some cases, higher material hardness is better; however, due to the hardness requirements of the machined parts, the material cannot be too hard. If it is harder than the machined parts, it cannot be machined.
Precision Machining Operation Steps
1. Finishing: This process mainly involves grinding and polishing, and is usually performed after the entire product structure is completed.
2. Machining Surfaces Before Holes: In precision mechanical parts manufacturing, especially for components like brackets, both surface machining and hole machining are required. To minimize the accuracy error of the machined holes, machining the surface first, followed by the holes, helps reduce errors.
3. Dividing Machining Stages: In precision mechanical parts manufacturing, different product requirements necessitate different levels of machining. If high precision is not required, a simple roughing stage is sufficient. As product requirements become more stringent, semi-finishing and finishing stages follow.
4. Datum First: When machining a product using mechanical equipment, a datum surface must be established. This provides a positioning reference for subsequent machining. After determining the datum surface, it must be machined first. Many precision mechanical parts are not produced in a single production run; when a part is manufactured, it is only a rough model.
