Bidirectional Screw

双向螺丝的模型，可以作为教具或者是益智玩具。我已将STP模型文件上传，欢迎下载并根据需要进行修改。The model of a bidirectional screw can be used as a teaching aid or an educational toy.I have uploaded the STP model file. You are welcome to download it and make modifications as needed.为我助力如果觉得有用，请为我助力，多谢多谢！If you find it useful, please give me a boost. Thank you very much!