In the wood sawing process, the front mouth of the band saw blade will be prolonged due to the impact friction of the wood. If the band saw blade does not have a rolling bending tendency, the swing of the front mouth of the saw blade will be aggravated, and the saw blade will not run straight and have a bend. The front of the blade is tight, which is beneficial to cutting. This is also an adjustment to the tension before and after.

　　Another advantage of the roll bending force is that when the two saw wheels are vertical, the saw blade is running in the middle of the saw wheel. To see the saw teeth, the upper wheel must be adjusted forward so that saw teeth can be exposed. After the wheel is adjusted forward, the trailing edge of the last wheel will be raised. At this time, if the band saw blade does not have a bending tendency, it will inevitably form a phenomenon that the back of the saw blade is tight and the front mouth is loose. With the bending tendency, the balance will be adjusted. This is another role of roll bending.