最新大胆西西人体44rtnet_精品人妻aⅤ中文字幕乱码_2019欧美日韩国产在线播放_亚洲最大天堂在线_偷拍三级久久精品_超碰国产一区二区三区_欧美野外性k8视频_黄网站免费高清一级视频_免费毛片高清完整版_日本黄色视频大全

Cold heading: According to the theory of metal plastic deformation, a certain pressure is applied to the metal blank at room temperature to cause plastic deformation in the mold cavity, and it is formed according to the specified shape and size. The pier is mainly used for mass production of fasteners such as nuts, bolts, etc. It has good surface quality, high dimensional accuracy, high efficiency and stable product quality.

For the upsetting of small precision parts, the mass production of non-standard screws for fasteners, etc., with high efficiency and obvious cost advantages