A driver device (hexalobe or otherwise) that includes a handle portion, an elongate shaft portion, and an end portion that includes a screw engagement portion and a split manufactured offset from the central axis of the end portion and/or the screw engagement portion, forming two asymmetric halves of the end portion and/or screw engagement portion. This screw engagement portion is slightly oversized relative to the corresponding tool engagement recess of the locking cap, set screw, or bone screw. Thus, when the screw engagement portion is pressed into the corresponding tool engagement recess of the locking cap, set screw, or bone screw, the split manufactured offset from the central axis of the end portion and/or the screw engagement portion allows the screw engagement portion to compress slightly, creating a friction fit between the screw engagement portion and the corresponding tool engagement recess of the locking cap, set screw, or bone screw.
