Main structure features
1. journal bearing. hardfaced head bearing surface. cone bearing inlaid with friction reducing alloy and then silver plated. the load capacity and seizure resistance of the bearing is greatly improved.
2. o- ring seal is made of the more wear resistance high saturated buna-N with the section and precissely designed sealing flange in the cone sealing area increased the reliability of the seal.
3. the bit bearing is ball which can be applied to high rotary speed drilling.
4. all rubber compensator is used which can provides the bearing system with good assurance of lubrication.
5. new type of grease that can sustain high temperature up to **0C is utilized.
6. high wear resistance and excellent cutting ability of the insert bit are given full play by using carbide compacts of high strength and high touhness in combination with optimized comjpact numbers and rows, the exposure height and special shaped compacts.

size: from **5/8"(**7.5mm)******1/2"(**4.5mm)
type:**7, **7, **7, **7, **7, **7

mark:sizes and types that are not shown in above, and can be customized according to specific drilling requirements