Turning, milling, planing, grinding, drilling, boring, what kind of precision can be achieved
01 Turning
The workpiece rotates, and the turning tool moves in a straight line or a curved line in the plane. Turning is generally carried out on a lathe to process the inner and outer cylindrical surfaces, end surfaces, conical surfaces, forming surfaces and threads of the workpiece.
The turning precision is generally IT8~IT7, and the surface roughness is 1.6~0.8μm.
1) Rough turning strives to use large cutting depth and large feed rate to improve turning efficiency without reducing the cutting speed, but the machining accuracy can only reach IT11, and the surface roughness is Rα20~10μm.
2) Semi-finishing turning and finishing turning should adopt high-speed and small feed rate and cutting depth as far as possible, the machining accuracy can reach IT10~IT7, and the surface roughness is Rα10~0.16μm.
3) High-speed fine-turning of non-ferrous metal parts with finely repaired diamond turning tools on a high-precision lathe can make the machining accuracy reach IT7~IT5, and the surface roughness is Rα0.04~0.01μm. This kind of turning is called "mirror turning" .
02 Milling
Milling is a high-efficiency machining method that uses a rotating multi-blade tool to cut a workpiece. It is suitable for processing planes, grooves, various forming surfaces (such as splines, gears and threads) and special surfaces of molds, etc. According to whether the direction of the main movement speed is the same as or opposite to the feed direction of the workpiece during milling, it can be divided into down milling and up milling.
The machining accuracy of milling can generally reach IT8~IT7, and the surface roughness is 6.3~1.6μm.
1) The machining accuracy during rough milling is IT11~IT13, and the surface roughness is 5~20μm.
2) The machining accuracy of semi-finish milling is IT8~IT11, and the surface roughness is 2.5~10μm.
3) The machining accuracy of fine milling is IT16~IT8, and the surface roughness is 0.63~5μm.
03 Planing
Planing processing is a cutting processing method in which a planer is used to perform horizontal relative linear reciprocating motions on a workpiece, and is mainly used for shape processing of parts.
The planing precision can generally reach IT9~IT7, and the surface roughness is Ra6.3~1.6μm.
1) The machining accuracy of rough planing can reach IT12~IT11, and the surface roughness is 25~12.5μm.
2) The machining accuracy of semi-finish planting can reach IT10~IT9, and the surface roughness is 6.2~3.2μm.
3) The machining accuracy of fine planting can reach IT8~IT7, and the surface roughness is 3.2~1.6μm.
04 Grinding
Grinding refers to the processing method of using abrasives and abrasive tools to remove excess material on the workpiece. It belongs to finishing and is widely used in the machinery manufacturing industry.
Grinding is usually used for semi-finishing and finishing, the precision can reach IT8~IT5 or even higher, and the surface roughness is generally 1.25~0.16μm.
1) The surface roughness of precision grinding is 0.16~0.04μm.
2) The surface roughness of ultra-precision grinding is 0.04~0.01μm.
3) The surface roughness of mirror grinding can reach below 0.01μm.
05 Drilling
Drilling is a basic method of hole processing. Drilling is often performed on drilling machines and lathes, and can also be performed on boring machines or milling machines.
The machining accuracy of drilling is low, generally it can only reach IT10, and the surface roughness is generally 12.5~6.3μm. After drilling, reaming and reaming are often used for semi-finishing and finishing.
06 Boring
Boring is an internal diameter cutting process in which a tool is used to enlarge a hole or other circular profile. Applications generally range from semi-roughing to finishing. The tool used is usually a single-edged boring tool (called a boring bar).
1) The boring accuracy of steel materials can generally reach IT9~IT7, and the surface roughness is 2.5~0.16μm.
2) The machining accuracy of precision boring can reach IT7~IT6, and the surface roughness is 0.63~0.08μm.
