Abstract: An expandable pipe line plug and tool are provided having a flexible stopper plug normally capable of insertion axially into a pipe to be sealed and expandable into sealing engagement with said pipe, said plug having an expandable portion actuated by relative movement of a nut and a threaded bolt having a circular head and landed shoulder beneath the head and a tool having an outer hollow member adapted to engage the nut at one end and an inner member axially of the hollow member having gripping means adapted in one position to pass over the circular bolt head and in a second position to engage the bolt head and landed shoulder whereby relative rotation of the outer hollow member and inner member causes relative rotation of the nut and threaded bolt to expand and contract the expandable member.