Drill Pipe - is heavy and seamless pipe that provides rotations for the down-hole assembly and circulates fluids. Drill pipe's both ends are threaded and called tool joints and normally bigger diameter than the pipe itself. This type of pipe is used on drilling rigs only. Drill pipe comes in different sizes, but normally less than 6”, with various grades of strength, weight and length. High torque requirements when rotating the down-hole assembly, drilling fluid pressure inside the drill pipe and bending loads when used in directional drilling, all create a massive amount of stress on the drill pipe. Hence, quality and the right selection of the drill pipe for a particular application is crucial. Too big, will not allow to flow the cutting smoothly, too small - not enough fluids going down the well.