High Quatity HSS-Co M35 Cobalt High Speed Steel Twist Drill Bit Set for Metal Woodworkingt Tool. Material: HSS-Co M35 Cobalt 5% Size. 5pcs:4,5,6,8,10mm. 13pcs:1.5, 2.0, 2.5, 3.0, 3.2, 3.5, 4.0, 4.5, 4.8, 5.0, 5.5, 6.0, 6.5mm. 15pcs:1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7, 8, 9, 10mm. 19pcs:1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0mm. 25pcs:1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0. 11.5, 12.0, 12.5, 13.0mm. The iron box is marked with the size of each drill bit for easy use. Handheld and Stationary Use (In Drill Press). 135 Degree Split Point Tip. HSS-Co Drill Bit Set for High Tensile Steels such as Stainless Steel. Suitable For: luminum, wood, malleable and deep hole drilling positioning holes iron. Difficult to machine the workpiece can be processed stainless steel, tool steel, through heat treatment. M35 cobalt high speed steel to obtain high hardness, high wear resistance and high toughness. Alloyed with Cobalt to improve heat resistance which will perform and outlast normal HSS bits particularly if your work involves drilling tough metals. Can be used radial drill, bench drill or hand drill chuck for drilling operations. The drill can drill stainless steel, but processing stainless steel and other high hardness of the workpiece, it is recommended to be fixed on the drilling machine or platform type machine, the use of electric hand drill is prohibited, because the artificial use of electric hand drill is easy to shake, resulting in insufficient processing accuracy Or the bit gets dull or even breaks. The bit and the workpiece to be processed must be fixed or clamped. Generally, the rotational speed is less than 2000RPM. The larger the diameter of the drilling hole, the lower the rotational speed. The harder the material is, the slower the speed is required, and the more durable the cutting fluid is recommended. Can dry cut stainless steel and other high hardness metal, but continuous uninterrupted work is best to add water or coolant cooling, prolong the life of the product. M35 drill bits(5/13/15/19/25pcs).