Qualified spiral blades not only require that the pitch of the inner warp and the outer diameter meet the standard, but also the arc standard is beautiful. We can meet the above requirements when we produce the blades through the cold rolling mill, but if the arc does not meet the standard, it cannot be called a qualified product. Friends who have operated a cold rolling mill may know that the outer diameter and pitch of the blade can be fine-tuned by the guide wheel. When the pitch is increased, the outer diameter needs to be smaller and the guide wheel can be moved in the opposite direction to complete the operation. If the arc of the curve is suitable, it can be adjusted in this way. If the arc is adjusted too large, it will be directly made into an inner or outer eight-character radian, that is absolutely impossible. It is necessary to re-adjust the spacing between the screws to perform the operation to complete the production of the final helix blade. purpose.