1Drill bit is made of titanium coating HSS and black chamfer part is steel, high hardness and wearable 2Drilling bit length can be adjusted for various length simply using the L-wrench 35 pieces set includes bits for drilling holes for different sizes of screws 4Can discharge wood sawdust more rapidly and smoothly in the process of drilling 5It is suitable for drilling on hard wood or any wooden products Description: This set is a necessary tool set to make a countersink or chamfer. In the process of using, they can discharge wood sawdust more rapidly and smoothly, and drill asmooth countersink for screws or nuts. With cone shaped bit, drilling is more convenient and faster. It is suitable for drilling on hard wood or any wooden products. Features: Drill bit is made of titanium coating HSS and black chamfer part is steel, high hardness and wearable. Drilling bit length can be adjusted for various length simply using the L-wrench. 5 pieces set includes bits for drilling holes for different sizes of screws. Can discharge wood sawdust more rapidly and smoothly in the process of drilling. It is suitable for drilling on hard wood or any wooden products. Specifications: Drill Material: Titanium Coating HSS 4241 Black Chamfer Body Material: Steel 45 Round Shank: 1/4" Dimension: Chamfer Part Drill Bit 6 2.38mm 8 2.78mm 10 3.175mm 12 3.56mm 14 3.97mm Weight: 70g(approx.) Package Includes: