This book is compiled according to the requirements of technical skills and theoretical knowledge for the advanced lathe worker in the revised national vocational qualification standard. This book introduces four modules, including machining long lead screw and worm, eccentric parts and multi-throw crankshaft, machining gearbox, and machining assembly, with tasks and subtasks in each module, with regard to the workpiece diagram recognition, processing analysis and calculation of various parts, such as long lead screw, multi-start thread, multi-line worms, double eccentric parts, four-throw crankshaft, gear reducer, worm gear reducer, bevel gears, bisector parts, mold, combined shaft and kit, as well as their clamping and positioning methods, processing methods, dimensional and geometric accuracy test methods, surface quality assurance methods, common quality problems and preventive measures or solutions, etc.This book can be used as a teaching book for mechanical, mechatronics,etc. app