Threads are formed in situ throughout a bore of a sleeve inserted into a corresponding hole in a substrate. A sleeve having a bore is inserted into a corresponding hole of a substrate. A mandrel is rotated through the sleeve. The mandrel has a threaded ended; the threaded end rotating throughout the bore of the sleeve forms threads throughout the bore. Prior to inserting the sleeve into the corresponding hole of the substrate, the sleeve can be placed onto the mandrel. In this case, the mandrel has an increasing diameter at the threaded end thereof, such that the sleeve rests on the mandrel towards the threaded end thereof where the bore has a smaller diameter than the mandrel. The mandrel is then rotated out of the sleeve in a direction opposite the direction in which the sleeve has been inserted into the corresponding hole of the substrate.