All Kennedy screwdriver bits have a hardness of 58 - 62HRC. High alloy chrome molybdenum steel for use on hand and power tools. Engineers’ Bit Set All?1/4” hex. x 25mm overall length, complete with magnetic spinner handle, 1/4” hexagon bit adaptor and 1/4” square socket adaptor. Hexagon: 2, 3, 4, 5, 6, 7 and 8mm. 3/32”, 1/8”, 5/32”, 3/16”, 1/4”, 7/32” and 5/16” Flat: 3, 4, 5, 5.5, 6.5 and 8mm. Crosspoint: No.1, 2 and 3. PZ: No.1, 2 and 3.