One: buy a good knurling knife, which is the key. The hardness of the knurling knife is very high. It is recommended to use the blade measuring tool factory in Chengdu, which has small gap and high hardness, and the rolled pattern is clear and beautiful. Two: the installation of the knurling knife should be centered like a turning tool, and it should form a small included angle with the workpiece, about 8 degrees, just like the auxiliary deflection angle of the turning tool, so that the knurling knife can easily cut into the workpiece. The knurling knife must be installed firmly, because the cutting force during knurling is much greater than that during turning, so in addition to moderately tightening the tool holder screws, the tool holder handle should also be pressed tightly. Three: Feed the middle carriage, and press the knurling knife on the workpiece, the force should not be too small, otherwise it is easy to produce random lines, but it should not be excessive, otherwise the workpiece will be deformed.