Description: The ladder of its unique structure, a bit can open a variety of specifications of aperture; Do not need to use center punch, compared with the ordinary twist drill is not easy to be broken; Deburring, chamfering, elliptic hole enlargement, twist drill, the function of them was unable, but it is possible; The usage of tools: drill, bench drill. Work while water cooling, can effectively extend the service life of drill bit; Great for drilling holes in sheet metal when you don't want to sort through a collection of drill bits; Specification: Material: High-speed steel 4241 Surface Treatment: Titanium Coated Dimension ( L x W x H ): 80 x 40 x 20mm/ 3.15 x 1.57 x 0.78'' Size for Each Piece: 4-12mm: 4, 6, 8, 10, 12mm 4-20mm: 4, 6, 8, 10, 12, 14, 16, 18, 20mm 3-12mm: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12mm Package Includes: 3 Pieces HSS Steel Drill Bit Set
