Mimgo Store 12pc/Set 1/4 Inch Length 50mm T5-T40 Magnetic Torx Electric Screwdriver Bits Tip. Type of head: Torx. Type of shank: 6.25mm / 1/4 inch hex. Size: T5, T6, T7, T8, T9, T10, T15, T20, T25, T27, T30, T40. Overall length.: 50mm / 2 inch. Those bits, magnetic that can be firmly fixed on screwdrivers, fit for electric screwdrivers, hand screwdrivers, electric drills, air drills and so forth. All torx bits have a centre bore except the size of T5 and T6.