For a welded built-up beam with a flange width of 12 inches, what is the allowed maximum off-center dimension for web placement?

In the context of welded built-up beams, the maximum off-center dimension for web placement is critical for maintaining structural integrity and ensuring that the beam can bear loads effectively. For a beam with a flange width of 12 inches, the maximum allowed off-center dimension for the web placement is typically defined by standards that aim to manage stress and prevent issues such as buckling and lateral-torsional instability.

The correct answer indicates that an off-center dimension of 1/4 inch (6mm) is permissible. This tolerance allows for minor deviations during construction and helps ensure that the web is appropriately aligned with respect to the flanges. If the web is too far off-center, it may lead to uneven stress distribution along the beam, thereby compromising its strength and performance.

The specified tolerance of 1/4 inch balances construction practicality while adhering to engineering principles. This value is commonly referenced in industry standards for maintaining the structural performance of built-up beams, which is why this choice aligns with accepted practices in welding engineering and construction.