Which of the following is the symbol for a standard I beam?

• A. H
• B. S
• C. I
• D. T

Answer: (B)

In structural drawings, beams are identified by letter codes that indicate their type. The letter S stands for standard beams, which include the common I-beams used in many constructions. The I-beam itself is named for its cross-section, but on drawings the symbol used to designate that standard beam is the letter S. Other symbols correspond to different shapes: H for H-beams, W for wide-flange beams, and T for T-sections. So the symbol for a standard I-beam in this context is S.