A fitting having three connections with the branch connection fixed at 90 degrees (1.5705 radians) to the run. the pipe connection(s) has standard pipe threads, or is unthreaded and designed to accommodate a pipe. the tube connection(s) has machine threads (straight threads other than pipe or hose series) designed to accommodate a tube, or is unthreaded and designed to accommodate a tube. it may have side inlet(s). it is used as a junction at the intersection of pipe or pipe fitting and a tube or tube fitting.