Draper 8 piece tx star bit set bit sizes t20 t25 t30 t40 t45 and t50 x 30mm t55 x 75mm set includes an assortment of 10mm tx star bits with 12 square drive x 10mm hexagon recess bit holding socket bits manufactured from silicon steel hardened and tempered with shot blast finish bit holder made from chrome vanadium steel hardened tempered and chrome plated for corrosion protection