美国Kennametal公司推出了直槽全硬质合金钻头系列.这种G系列钻头用细晶粒硬质合金制成,无需中心钻孔,尺寸与配置的范围均宽,标准直径3～16mm,在切穿斜面与其他难加工表面时不会“走移”.如G—7型钻头有两个铰孔刃口,无需后道铰孔. American Kennametal company introduced a series of straight trough all carbide drill. The G series drill bit made of fine grain cemented carbide, without central drilling, the size and configuration of a wide range of standard diameter of 3 ~ 16mm, cutting Do not “go” when wearing bevels and other difficult-to-machine surfaces, such as G-7 drills with two reaming edges, eliminating the need for rear reaming.