LAXMI manufactures short length Drill Collars in all outer dia. Size strictly as per A.P.I. Specification, these are made from alloy steel AISI 4145 H and heat treated to meet the specified properties.
The precision threads on all drill coller connections meet or enceed API Specification. Threads are kemplated to prevent galling during make-up, than thread protectors are installed. API relief groves an pin or bore back are available upon request.
Both connections are cold working increase the endurance limit of a connection.

Rethreading of Drill Collars & Drill Pipe are cut on oil country lathe machine. Threads are cut with a constant profile tool to ensure the highest accurancy possible. Threads are cold rolling is systematically carried out on a special machine to improve mechanical properties of the connections. Before thread cutting, ends are tested for fatigue cracks. To prevent galling, the threads are phosphatized.