Diamond exploration coring drill bit NQ HQ PQ BQ AQ pdc for coal drilling Introduction

1.1 Heat treatment control:

Heat treatment will greatly improve the material strength and increase the thread wear life

of the rods and casings. We conduct either tru-wall or both ends heat treatment to the

tube body. After heat treatment, strength, hardness, straightness and concentricity of the

treated tubes will be tested in our lab.

1.2 Thread opening process:    

Accuracy of threads will determine the use effects and life time of drill rod and casings.   

CNC latches and form cutter are used in thread opening processing to minimize error 

made by anthropic factors. 

1.3 Additional thread treatment: 

Surface of the threads will be cleaned to remove burr adhered after threads are opened. 

Afterwards, the tread surface will be phosphated to improve surface conditions.