Hercules, 1/4 PT, Grip Thread, All Purpose Sealant, Tough, Pliable, Non-Petroleum Based Seal For Joints, Valves, Flanges, & Gaskets, Brushable, Non-Separating, Sets Up Quickly & Dries To Form A Very Tough, Yet Flexible Seal Which Will Not Harden, Crack, Crumble, Or Shrink, For Use On Metals, Including Galvanized Steel, Black Iron, Aluminum, Copper, Brass, Stainless Steel, & On PVC, CPVC, ABS, & Plastics.