Abstract: A key for locking a threaded insert in a carrier material is provided with an improved tang portion. The improved tang portion includes spring retention means for reducing the friction required to position and hold the key within an insert slot prior to final installation and provide superior driveability over known prior art keys. The spring retention means includes a flexure area and a pair of protrusions which are held by spring force against the walls of the insert slot. The flexure area is centrally located on the tang portion and includes an aperture therein.