Bulroc drill tubes are produced from high quality seamless pipe. They are designed to the highest standards using the thinnest wall section material but without the loss of the necessary strength to give the closest ratio of weight to durability. Tool joints of high alloy steel are nitrited to provide a hardwearing surface for longer thread life. All Bulroc drill tubes are friction welded to give the strongest and most consistent form of welding to ensure long life and dependability. Thread protectors are fitted to both pin and box ends of all Bulroc drill tubes that are finished with a protective surface coating. Bulroc also produce Combined Cased Drill Tubes which are required when drilling large diameter holes with relatively small diameter drill tubes, using air as a flushing medium.