Turning, milling, planing, grinding, drilling, boring, the highest precision of these machine tools and the tolerance levels that can be achieved by various processing methods are different. Next, we will take you to understand the highest machining accuracy that some major machine tools can achieve.

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 and finishing turnings use high-speed and small feed rate and cutting depth as much as possible, the machining accuracy can reach IT10-IT7, and the surface roughness is Rα10-0.16μm.

3) Using finely repaired diamond turning tools on high-precision lathes for high-speed fine-turning of non-ferrous metal parts, the machining accuracy can reach IT7-IT5, and the surface roughness is Rα0.04-0.01μm. This kind of turning is called “mirror turning” “.

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 the same or opposite direction of the main movement speed and 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) Machining accuracy IT11-IT13 during rough milling, surface roughness 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.

Planing

Planing processing is a cutting processing method in which a planer is used to make a horizontal relative linear reciprocating motion on the workpiece, and is mainly used for the 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 planing can reach IT10-IT9, and the surface roughness is 6.2-3.2μm.

2) The machining accuracy of fine planing can reach IT8-IT7, and the surface roughness is 3.2-1.6μm.

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 accuracy 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.

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 only up to IT10, and the surface roughness is generally 12.5-6.3 μm. After drilling, reaming and reaming are often used for semi-finishing and finishing.

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.

Note

Machining accuracy is mainly used to characterize the fineness of the produced product, and it is a term for evaluating the geometric parameters of the machined surface. The standard for measuring the machining accuracy is the tolerance level. There are 20 tolerance levels from IT01, IT0, IT1, IT2, IT3 to IT18. Among them, IT01 indicates the highest machining accuracy of the part, and IT18 indicates the lowest machining accuracy of the part. Generally, factories and mines Machinery belongs to IT7 level, and general agricultural machinery belongs to IT8 level. According to the different functions of the product parts, the processing precision that needs to be achieved is different, and the selected processing form and processing technology are also different.

Hope the above content is helpful to you!