Abstract: To facilitate the casting of stronger and more precise steel reinforced concrete members and also to facilitate the formation and field joining of such members there is provided a bar splice which comprises a generally cylindrical sleeve open at one end to form an axially elongated chamber to receive a steel reinforcing bar telescoped therein, and provided with internal threads at the other end whereby a threaded bar end may be secured to the other end, and when secured sealing the other end of the chamber. The threads are preferably tapered and the chamber includes inwardly extending axially spaced annular ribs. Lateral ports are provided at each end of the chamber. The wall thickness of the chamber adjacent the threaded end of the sleeve may be increased to improve tensile capabilities. The length of the chamber is most of the splice sleeve since the threaded connection occupies little axial space.

Abstract: To facilitate the casting of stronger and more precise steel reinforced concrete members and also to facilitate the formation and field joining of such members there is provided a bar splice which includes a generally cylindrical sleeve open at one end to form an axially elongated chamber to receive a steel reinforcing bar telescoped therein, and provided with internal threads at the other end whereby a threaded bar end may be secured to the other end, and when secured sealing the other end of the chamber. The threads are preferably tapered and the chamber includes inwardly extending axially spaced annular ribs. Lateral ports are provided at each end of the chamber. The wall thickness of the chamber adjacent the threaded end of the sleeve may be increased to improve tensile capabilities. The length of the chamber is most of the splice sleeve since the threaded connection occupies little axial space.

Abstract: A machine for taper threading the end of a bar such as reinforcing bar used in concrete construction utilizes a power operated vice to clamp and feed the bar end axially into a rotary head which contains chaser tooling holders which open uniformly on the bar end as the head rotates. The rotary head is axially stationary but contains an axially movable key or linear cam which engages a readily removable transversely extending control rod assembly in turn moving the chaser holders. Axial movement of the power vice and thus the bar end at a controlled axial speed with respect to the rotary speed of the head moves the key to cause the movement of the chaser holders. The chaser holders in addition to supporting the thread cutting chasers also support ahead of the chaser an indexable triangular insert to pre-cone the bar end.