Since CNC lathes are high-end products with new technology, involving many professional knowledge fields such as mechanics, electrical, hydraulics, pneumatics, optics and computer technology, the choice of turning tools for CNC lathes must meet the standards:
1. For fine turning, it is best to choose a sharpened blade. This kind of blade has better dimensional accuracy, so the positioning accuracy of the blade in turning is higher, and better machining accuracy and surface roughness can be obtained. In addition, the development trend of grinding turning inserts used in finishing is to grind out the chip flutes to form a large positive cutting edge, allowing the insert to cut at a small feed and a small depth of cut. However, for carbide inserts without sharp rake angles, when small feed and small depth of cut are used, the tool tip will rub against the workpiece and the tool life will be short.
2. In some processing occasions, it is more appropriate to choose a pressed blade, and sometimes it is necessary to choose a ground blade. It is best to choose a pressed blade for roughing, which can reduce the processing cost. The dimensional accuracy and edge sharpness of the pressed blade are worse than that of the ground blade, but the pressed blade has better edge strength, impact resistance during rough machining, and can withstand greater depth of cut and feed. The pressed blade sometimes has a chip groove on the rake face, which can reduce the cutting force, and at the same time, it can reduce the friction with the workpiece and the chip, and reduce the power demand.
3. However, the surface of the pressed blade is not as tight as the sharpened blade, and the dimensional accuracy is poor. The height of each tool tip on the turning tool body is quite different. Because the pressed blade is cheap, it is widely used in production.
4. The ground blade with large rake angle can be used to turn viscous materials (such as stainless steel). Through the shearing action of the sharp blade, the friction between the blade and the workpiece material is reduced, and the chips can leave the front of the blade faster.
5. As another combination, the pressed blade can be installed in the blade seat of most turning tools, and a polished scraper blade can be configured. The squeegee blade removes rough machining knife marks, and can obtain better surface roughness than only the pressing blade. Moreover, the use of doctor blades can reduce cycle time and reduce costs. Scratching technology is an advanced technology that has been widely used in the fields of turning, grooving and cutting and drilling.