Drill Collars are the most important parts of all drilling string elements. The performance of drill collars will effect the efficiency of drilling. Zyzxdy mission is to provide our clients with most cost-effective products, not only price, but also products performance. We assure every piece of Drill Collar leaving our facility conform to the requirements of API SPEC 7-1. When producing, Traceability  Are maintained from the receipt of raw material to completion of  Final products. Serial numbers are die-stamped on each bar body.

During each manufacturing process, test and inspection are performed. We do Ultrasonic Testing and Magnetic Partical Testing before and after Heat Treatment. Specimen have been taken from each  Bar after  Heat-treatment to make Tensile Test and Impact Test. We assure the Mechanical Properties of our products comply with or exceed the requirements of API.