Reinforcing Y-Bar – 20mmReinforcing Y Bar 20mm Rebar (short for reinforcing bar), collectively known as reinforcing steel and reinforcement steel, is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and hold the concrete in compression. Concrete is strong under compression, but has weak tensile strength. Rebar significantly increases the tensile strength of the structure. Rebars surface is often patterned to form a