... , and toughness, when drilling the homogeneous formation, the lip of GK can scrape the stratum, and the spherical prominence can control ... 50 times of impact. 2)wear ressistanceThe abrasion ressistance of GK is highly improved by using the superfined diamond powder and ... . Advantages:1.The helmet shape design and advanced techniques make GK cutters apply to ravelly ground with higher impact resistance.2 ...