The design of the Tapcon® concrete screw allows them to anchor into concrete, brick and block. Tapcon® concrete screws tap threads into a predrilled hole in concrete, brick or block. The 5/32" bit is used for the 3/16" Tapcon® concrete screw and the 3/16" bit is used for the 1/4" Tapcon. These bits can be used for either the standard blue Tapcon or the stainless steel Tapcons. The large diameter Tapcons use regular ANSI standard bits.