1/4" Sq.Dr. Nut-Grip SAE Short Socket Rail Set, 6 pcs.Nut Grip, 1 4" Drive, Chrome Hand Socket Set. NUT GRIP is Ko ken's special design for non magnetic nuts bolts to be held firmly in a 6 point socket. The design consists of two balls held in place by a spring steel ring. Our nut grip sockets are unique to Ko ken and truly a revolutionary way of approaching this type of socket. Our fastener holds nuts and bolts in place without the use of magnets. Our system is built with a coil spring and ball bearings