Prevent grate displacement from heavy runoff flows, pedestrian and vehicular traffic, as well as deter theft and vandalism by securing the ductile iron drain grate to the BG-FILCOTEN® 300 trench drain channel body with these specialty bolts and nuts. Four bolts and nuts are required to bolt to the four points located in the corners of the drain grate. Hex-head bolts can be secured with a hex socket screwdriver. Comes with one bolt and one nut.