First, check whether the position of the nut support surface on the back of the hexagonal flange should be parallel and smooth. If there are scratches, nicks, mud, corrosion and burrs, the flange nuts must be replaced or reworked. When installing the hex nut flange, first find the hole where the nut can be installed, then align the hole and insert it, and then slowly turn it clockwise until it is tightened.