我所拼装组合式牙轮钻头及滚刀钻头是全国大口径施工的主导产品汇集原PZ、AF、ZH、JKZ、ZY等钻头全部优点国内首创双支点牙轮极大改善了牙轮受力状况和耐磨性＊彻底消除了掉牙轮掌给施工带来的不便＊寿命比普通牙轮提高一倍以上＊利用电脑布齿，钻进效率更高＊导流和漫流结构使 Our combined cone roller bits and hob bits are the leading products of large-caliber construction in China. All the bits of the original PZ, AF, ZH, JKZ, ZY and other drills have the same advantages. And wear resistance * Completely eliminate the inconvenience of the fall of the tooth palms to the construction * Life expectancy more than double the ordinary roller * Use of computer cloth teeth, drilling more efficient * Diversion and diffuse structure