What is the minimum bend diameter of a number 9 standard hook in tension?

The minimum bend diameter for a number 9 standard hook in tension is indeed 9 inches. This specification is based on guidelines set forth in the relevant building codes and standards for reinforced concrete, which aim to ensure both the structural integrity and the workability of the reinforcement.

The minimum bend diameter is critical because it affects the mechanical properties of the rebar as well as the anchorage of the hook. A bend that is too tight could induce excessive stress concentrations leading to cracks or failures in the concrete, while a proper bend diameter ensures that the rebar can adequately transfer loads and maintain its intended strength and ductility.

In this case, selecting 9 inches as the minimum bend diameter reflects an understanding of these principles and ensures compliance with standards for concrete reinforcement, which is crucial for safe and effective construction practices.