scope:

GENERAL Wobble gaging provides a means for determining the compatibility of the Type 1A cross recesses formed into the heads of screws with companion screw drivers or power driver bits and will indicate the point where deviations in the recess contours affect satisfactory driver engagement. Recesses which exhibit excessive wobble characteristics will result in poor screw drive ability because of driver cam out prior to attaining the normal torque level, damage to the recesses, and/or accelerated driver wear.