牙轮 E
1、低抗压强度和分层软到中等地层；
2、高抗压强度和磨蚀性薄互层介质至硬地层
3、高抗压强度和中等磨蚀性坚硬致密地面
1.Low compressive strength and layered soft to medium formations
2.High compressive strength and abrasive thin interbedded medium to hard formation
3.High compressive strength and medium abrasive hard and compact ground
