基于变螺距螺纹加工的普通机床改造
The Reforming of Machine Tool Based on Machining for Varying Pitch Screw
大尺寸钢管端部螺纹加工专用数控机床
A NC Machine Tool for Screw Process at Long-size Steel Tube Ends
螺纹加工机床螺纹加工机床螺纹加工机床