What does the grade number on reinforcing steel represent?

The grade number on reinforcing steel is indicative of the tensile strength of the bar. In the context of reinforcing steel, the grade designation helps to identify the yield strength of the steel, which is a critical factor for determining how the material will behave under stress. Higher grade numbers correspond to greater tensile strengths, meaning these bars can withstand larger loads before failing. This specification ensures that the right material is used for particular construction requirements, allowing engineers to design structures that meet safety and performance standards.

While other options may seem relevant in different contexts (like the length or diameter of the bar), the grade number itself is specifically tied to the mechanical properties of the material, particularly its ability to resist tension. This distinction is crucial for ensuring that the reinforcing steel provides adequate support in concrete applications, enabling structural integrity.