The 13-piece Torx socket set includes a forged chrome vanadium steel socket and S2 forged steel forges for torque, strength and durability Dr. 1/4" bit - Chrome vanadium sockets provide maximum resistance to oil and corrosion bit Forged S2 steel bit, heat treated, provides torque, strength and durability, Size: T8, T10, T15, T20, T25, T27, T30 Dr. 3/8" bit - Chrome vanadium plated sockets provide maximum resistance to oil and corrosion bit Forged S2 steel bit, heat treated, ensuring torque, strength and durability Size: T40, T45, T50, T55 T60 Dr. 1/2" bit - Chrome plated vanadium sockets provide maximum oil and corrosion resistance. Forged S2 steel drill bit, heat treated, ensuring torque, strength and durability, Size: T70 Package Includes - All pieces in this set fit neatly into a durable blow molded carrying case for easy organization and convenient portability