The DI22 series of threaded connections was designed specifically for the raiseboring industry. The tapered design of the DI22 threaded connections allows for connections to be self-centred prior to engagement. Self-centering reduces the chance of cross threading or other damage during engagement. The coarse thread profile is capable of withstanding the extreme torsional and thrust loads that are applied during reaming. Properly lubricated and torqued, DI22 threaded connections will provide many years of trouble-free operation.
In recent years, the DI315 series of threaded connections was developed to meet the needs of the industry as larger, more powerful drills were designed. The unique thread profile and pitch of the DI315 threaded connections were designed to transmit higher levels of torque and thrust than the DI22 series, without the need for a drastic increase in pipe diameter.