20" IADC537 new big size hole opener bit/reamer/Assemble reamer bits for rock drilling horizontal directional

1.The durability of premium tungsten carbide inserts are improved with new formulas and new techniques for insert bit;
2.Sliding bearing forms, palm-axis surfacing tooth carbide layer, inner cone hole silver;
3.Bearing O-ring wear-resistant, high-temperature high in saturated nitrile rubber;
4.Adopt limit the pressure and prevent drilling fluid into the lubrication system-wide rubber reservoir bag;
5.Use of high strength and high toughness carbide teeth.