A hydraulic tensioner for preloading threaded studs or bolts has a cylinder and piston assembly at the top with a spherically concaved bottom surface overlying a matching spherically convex top surface of the supporting pedestal. Said assembly is held spaced above the pedestal by counterbalancing springs when the tensioner is unloaded but is pulled down to engage said surfaces when the tensioner is loaded. Said assembly and the drawbar, engagement nut and related components are angularly movable.