91亚洲狠狠婷婷综合久久久Ih视频日本Ifreexxx丝袜办公室hdI超黄视频网站I精品亚洲欧美一区I欧美 激情在线I98涩涩国产露脸精品国产网I亚洲专区在线视频I一级亚洲I91红桃视频I一区五区电影I亚洲成人7777777I一区二区三区四区五区I国产精品A片I国产精品视频永久免费播放I久久视频在线I你懂的在线视频I亚洲H天堂

The first is the requirements for Hardness. For some occasions, the higher the hardness of the material, the better. It is only limited to the hardness requirements of the machined parts. The machined materials cannot be too hard. If they are harder than the machined parts, they cannot be machined.
Secondly, the material should be moderately soft and hard, at least one grade lower than the hardness of the machine parts, and it also depends on the purpose of the processed components and the reasonable selection of materials for the machine parts. In short, precision machining still has certain requirements for materials, and not all materials are suitable for processing, such as materials that are too soft or too hard. The former is not necessary for processing, while the latter cannot.
So, the basic rule is to pay attention to the density of the material before processing. If the density is too high, it is equivalent to a high hardness. If the hardness exceeds the hardness of the machine (lathe tool), it cannot be processed. Not only will it damage the parts, but it will also cause danger, such as the tool flying out and injuring people. So, generally speaking, for mechanical processing, the material material must be lower than the hardness of the machine tool in order to be processed.