[M12]

As synonymous with loosening nuts, the U-Nut is widely supported in the industry, and is useful in a variety of industries, including steel structures such as railways and bridge beams, cars, motorcycles, and industrial machinery.
When tightened, the friction ring will be ground to the bolt thread. Then along the thread, the friction ring begins to sag and press the bolt screw face. The pre-beling torque (friction torque) generated by the pulling force (reverse) of the screw on the bolt nut, which acts as a loosening action.