At the reactive side of the flange there is often an opposite nut. This nut rotates and needs to be kept stationary by a back-up wrench that abuts against a solid object. The HYTORC Back-up Washer is the easiest way to keep the opposite nut in place. The result is the same as when using a back-up wrench of slogging wrench, but then without any safety risks. This smart washer is placed between the flange surface and the nut, just like any ordinary washer. The knurled surface of the HYTORC Washer becomes one with the flange and nut, eliminating the need for a back-up wrench. This means no more pinch hazards.