Drill collar is one of ETANG's main products. With high-quality 4145H/4145H-Mod/Non-magnetic alloy raw materials and excellent machining capabilities, ETANG drill collars are widely used in oilfield drilling equipment around the world.

　　Spiral Groove:

　　To reduce the pressure difference, the surface of the drill collar can be spiral. Compared with the smooth standard drill collar, the weight loss of the spiral drill collar is about 4%.

　　Stress Dispersion Groove & Bore Back Box:

　　The stress dispersion groove improves the bending strength of the pin and box connection, thereby improving its durability.

　　The Bore Back Box achieves a gradual reduction in the internal diameter by gradually increasing the cross-sectional area of the material at critical section. Therefore, under the action of static/dynamic loads, the stress concentration phenomenon is greatly alleviated, and the failure frequency is greatly reduced.

　　Hardbanding:

　　ETANG provides the following wear-resistant materials: Arnco-100xT, Arnco-300xT, TCS-8000;

　　Slip and elevator recess:

　　Slip and elevator recess improve downhole processing efficiency and safety, and ETANG processes them according to API 7-1.