Carbide Standard 2 Blade High-speed 33mm Drill Bits 1Identified by Zoller 2TiALN coating 3Special for drilling hard metal Tungsten Carbide Standard 2 Blade High-speed 33mm Drill Bits1Indentified by Zoller2TiALN coated improve the cutter life3Better resistance in hardness and toughness4Special for drilling hard metal 1.The feature of high-speed drill bits:--the diameter of flute: 0.5-9.5 mm--the ...