What is the highest machining accuracy of the machine tool ？
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- Issue Time
- Aug 16,2020
Summary
Machining accuracy is mainly used to characterize the fineness of the produced product and is a term used to evaluate the geometric parameters of the processed surface. According to the different functions of the product parts, the machining accuracy that needs to be achieved is different, and the selected processing form and processing technology are also different.
What is the highest machining accuracy of the machine tool ？
Turning
The workpiece
rotates, and the turning tool performs cutting processing of linear or curved
movement in the plane. Turning is generally performed 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 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) For semi-finishing and finishing turning, try to use
high-speed and small feed and cutting depth, the machining accuracy can reach
IT10-IT7, and the surface roughness is Rα10-0.16μm.
3) High-speed precision turning of non-ferrous metal parts with a
fine-refined diamond turning tool 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".
Milling
Milling refers to the use of rotating multi-edge tools to cut
workpieces, and is a highly efficient processing method. It is suitable
for processing planes, grooves, various forming surfaces (such as splines,
gears and threads) and special shapes of molds. According to the same or
opposite direction of main motion speed and workpiece feed direction during
milling, it is divided into down milling and up milling.
The machining accuracy of milling is generally up to 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 finishing milling is IT16—IT8, and the surface roughness is 0.63—5μm.
Grinding
Grinding is usually used for semi-finishing and finishing, and
the precision can reach IT8-IT5 or even higher. 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
carried out on drilling machines and lathes, but also on boring machines or
milling machines.
The machining accuracy of drilling is low, generally only
reaching IT10, and the surface roughness is generally 12.5-6.3μm. After drilling, reaming are often used for semi-finishing and
finishing.
Boring
Boring is an inner diameter cutting process that uses tools to
expand holes or other circular contours. Its application range generally ranges
from semi-rough machining to finishing. The tools used are usually single-edged
boring tools (called boring bars).
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.