Abstract: A rod joint in which the entire threaded length connection between two substantially straight rods, without shoulders, is pre-stressed, including a split, sectioned ring which fits between preformed seats on each of the rod elements.

Abstract: A valve seat may be formed deep within a valve body by attaching a wear-resistant material to a base material, such as by welding. Similarly, a drive member may be attached to either of the wear-resistant material or the base material. The thus-assembled structure can be rotated at high speeds adjacent a welding seat located deep within the valve body to create a friction or inertia weldment between the seat and base material. Subsequently, the drive material, weldment flash, etc., can be machined away and the wear-resistant material can be machined, if necessary, to create a valve seat of predetermined configuration.