Henan Zhongyuan Roller Shaft Co., Ltd. [China]

Detailed Product Description

Based on API Spec.7 and SY/T5144, the spiral drill collars are made of 4145H modified chromium molybdenum alloy steel. All threads are phosphated, copper zed or cold rolled. All threads machined with CNC Lathes Double shoulderd, including some special threads. The maximum outer diameter of drill collars can amount to 14 inch.