What is the diameter in inches of a #8 bar?

The diameter of a #8 rebar is 1 inch. This sizing information comes from the standard rebar sizing convention, where the number designation does not directly correspond to the diameter in inches, but rather is indicative of its size in a specific system. Each number represents a tenth of an inch in diameter. Therefore, a #8 bar, which is 8/8 inches, simplifies to 1 inch.

Option A represents a much smaller diameter than what is standard for a #8 bar. Option C, at 1.5 inches, exceeds the actual diameter, and Option D is even larger, resulting in a substantial deviation from the correct size. Understanding these dimensions is crucial for proper structural applications, ensuring that materials used meet the required specifications for strength and load-bearing capacity.