免费国产视频_亚洲国产女人精品久久久_国产欧美日产A片_91porn国产_欧美精品久久久久久久久久丰满_日日日夜夜操_91熟妇视频_精品探花对白视频在线观看,97久人人做人人妻人人玩精品 ,91露脸熟女对白不带套,正在播放日韩一区二区

Product introduction Hardware shrapnel is a mechanical part that uses elasticity to work. Generally made of metal shrapnel steel. It is used to control the movement of parts, alleviate impact or vibration, store energy, measure the size of force, etc. It is widely used in machines and instruments. The types of hardware shrapnel are complex and diverse. According to the shape, they mainly include positive contact, power supply shrapnel, and contact mother shrapnel. Hardware shrapnel belongs to the category of metal stamping parts and electronic hardware materials. It is made of stainless steel or manganese after heat treatment. It is an important part of the switch. With the help of the conductivity of the metal shrapnel, it can play a high-quality switch between the operator and the product. At the same time, using the stable resilience of the guozi (automatically return after pressing), and the long life, provide the operator with high-quality tactile feedback!