The Kahn System is an industrial construction technique for reinforcement of buildings that was engineered and patented by Julius Kahn. The Kahn system is an industrial construction design using the Kahn Trussed Bar as the bases. This steel bar was a new type of reinforcing bar used in concrete and had unique engineered features to distribute stress.Kahn saw problems with the concrete reinforcement systems used in building construction at the end of the nineteenth century.