Standard taper thread couplers are designed to splice the same diameter bars where one bar can be rotated and the bar is not restricted in its axail direction. It is designed to achieve failure loads in excess of 115% of the charateristic strength of grade 500 rebar end. Working principle: 1. Slice up the end of the rebar. 2. Make the rebar taper thread cut by taper thread machine. 3. Connect together two taper thread end by one piece of taper thread coupler.