TORX HEAD: T30 (2.5″L), T27 (2.5″ L), T20 (2.5″L). HEX BALL: HB6 (3.5″L), HB5.5 (3.5″L), HB4 (3.5″L), HB5/16″ (5″L), HB1/4″ (5’L), HB7/32″ (5″L), HB3/16″ (5″L), HB5/32″ (5″L). The 25 pc. Impact Grade Bit Drivers are made from an industrial grade steel and heat treated to the impact grade standard to improve torsional performance over ordinary bits.