For accurate dimensions of specified beams, what should always be referred to?

The most reliable source for accurate dimensions of specified beams is the steel manufacturers' dimension tables. These tables are created based on the specific design and manufacturing processes of the steel, providing precise measurements and specifications for different types of beams. They include critical information such as weight per foot and load capacities, which are essential for ensuring that the beams will perform as intended in structural applications.

Referring to steel manufacturers' dimension tables helps prevent errors that could arise from using outdated or generalized information, ensuring that the materials used meet all necessary engineering standards for safety and performance. Additionally, they typically contain the latest updates and developments in steel products, making them the most current and relevant resource for construction professionals.

While local building codes, drafting standards, and general industry guidelines all play important roles in the construction process, they do not provide the specific dimensional data that is crucial for accurately selecting and using beams in a project.