Rebar couplers are used in reinforced concrete structures to replace normal rebar lap joints. The couplers are also suitable for use in reinforced concrete columns and walls. Each rebar coupler consists of a piece of rebar equipped with a thread and coupler sleeve at the right end as viewed in the direction of installation. In construction joints, rebar couplers can be used to replace all pieces of rebar going through the formwork. Rebar couplers are used for joining rebars with full tension capacity. The ends of bars to be joined are provided with threads, and the bars are joined using a coupler sleeve that transfers the force on the rebar across the connection.