A grip lock connector member which connects a supply pipe from a source of water to a fire sprinkler through an interior grip lock connector. The grip lock connector includes a multiplicity of gripper teeth which form a tight grip connection to the supply pipe. The supply pipe is retained within an interior chamber and grasped and retained by the multiplicity of gripper teeth at the interior end of the interior chamber. A gasket or O-ring directly behind the gripper teeth facilitates a leakproof connection. At its opposite end, the grip lock connector includes female mating threads which receive male threads at a top location of a fire sprinkler.