タイトルまたは説明

According to API Spec.7 and SY/T***4, drill collar is made of AISI ***5 modified chromium- molybdenum alloy steel. All threads are phosphated, copperized or cold rolled , and they are machined with CNC Lathes –Double –shoulderd, including some special threads. We can supply drill collars in length from *0 to *5 feet and outside diameter from **1/8" to *1".The maximum outer diameter of drill collars can amount to *4”. Elevator and slip recesses To meet customers’ requirement, elevator and slip recesses can be machined on drill collars according to API specifications.