Cutting refers to
Cutting tools (including cutting tools, abrasive tools and abrasives) are used to cut off the excess material layer on the blank or workpiece into chips, so that the workpiece can obtain the specified geometric shape, size and surface quality.
What the host wants to know is the classification of cutting
There are many classification methods for cutting metal materials. There are three common ones.

According to process characteristics 　　
The technological characteristics of cutting are determined by the structure of the cutting tool and the relative motion form of the cutting tool and the workpiece. According to technological characteristics, cutting processing can generally be divided into: turning, milling, drilling, boring, reaming, planing, slotting, broaching, sawing, grinding, grinding, honing, super finishing, polishing, gear Machining, worm gear machining, thread machining, ultra-precision machining, fitter and scraping, etc.

According to the removal rate and accuracy, it can be divided into:
①Rough machining: Use a large cutting depth to cut most or all of the machining allowance from the workpiece through one or a few passes, such as rough turning, rough planing, rough milling, drilling and sawing, etc., rough machining The processing efficiency is high and the processing accuracy is low. It is generally used for pre-processing, and sometimes it can also be used for final processing.
②Semi-finish machining: generally used as an intermediate process between rough machining and finishing, but the parts on the workpiece that do not require high precision and surface roughness can also be used as final machining.
③ Finishing: Use fine cutting to achieve higher precision and surface quality on the machined surface, such as fine turning, fine planing, fine reaming, and fine grinding. Finishing is generally final processing.
④Finishing: It is carried out after finishing, the purpose is to obtain a smaller surface roughness and slightly improve the accuracy. The finishing processing has a small machining allowance, such as honing, grinding, super-finishing and super-finishing.
⑤ Modification processing: The purpose is to reduce the surface roughness, to improve the anti-corrosion, dust-proof performance and improve the appearance, but does not require increased precision, such as polishing, sanding, etc.
⑥Ultra-precision processing: some special precision parts are required in cutting-edge technology fields such as aerospace, laser, electronics, nuclear energy, etc. The precision is as high as IT4 or more, and the surface roughness is not greater than Ra 0.01 micron. This requires special measures for ultra-precision machining, such as mirror turning, mirror grinding, and soft abrasive mechanical chemical polishing.

According to the surface forming method 　　
During cutting, the machined surface of the workpiece is obtained by the relative movement of the cutting tool and the workpiece.

According to the surface forming method, cutting can be divided into three categories.
① Tool tip trajectory method: Relying on the motion trajectory of the tool tip relative to the surface of the workpiece to obtain the surface geometry required by the workpiece, such as turning the outer circle, planing the plane, grinding the outer circle, turning the forming surface with a master, and so on. The trajectory of the tool tip depends on the relative movement of the cutting tool provided by the machine tool and the workpiece.
②Forming tool method: abbreviated as forming method, the forming surface is processed with a forming tool or a forming wheel that matches the final surface profile of the workpiece. At this time, part of the forming motion of the machine tool is replaced by the geometry of the blade, such as forming turning, forming milling and forming grinding. Due to the difficulty of manufacturing forming tools, the cutting force that the process system formed by machine tools-fixtures-workpieces-tools can withstand is limited, and the forming method is generally only used for processing short forming surfaces.
③Generation method: also known as the hobbing method. During processing, the cutting tool and the workpiece make relative generative motion, and the instantaneous center line of the tool (or grinding wheel) and the workpiece make pure rolling with each other, and a certain speed ratio relationship is maintained between the two. The machined surface obtained is the envelope surface of the blade in this movement. Gear hobbing, gear shaping, gear shaving, gear honing and gear grinding (not including shaping gear) are all generative processing.