What is the nominal diameter of a No. 5 rebar?

What is the nominal diameter of a No. 5 rebar?

• A. 1/2 inch
• B. 5/8 inch
• C. 3/4 inch
• D. 7/8 inch

Answer: (B)

Rebar uses a numbered system where the number identifies the bar’s nominal diameter in inches, giving engineers a quick way to know the cross-sectional area. For a No. 5 bar, the nominal diameter is 5/8 inch (0.625 in). This value is used in design calculations to determine the steel area and spacing, even though the bar has ribs that affect its actual exterior texture. The numbers map to other diameters as well: No. 4 is 1/2 inch, No. 6 is 3/4 inch, No. 7 is 7/8 inch. So 5/8 inch is the correct nominal diameter for No. 5.

Rebar uses a numbered system where the number identifies the bar’s nominal diameter in inches, giving engineers a quick way to know the cross-sectional area. For a No. 5 bar, the nominal diameter is 5/8 inch (0.625 in). This value is used in design calculations to determine the steel area and spacing, even though the bar has ribs that affect its actual exterior texture. The numbers map to other diameters as well: No. 4 is 1/2 inch, No. 6 is 3/4 inch, No. 7 is 7/8 inch. So 5/8 inch is the correct nominal diameter for No. 5.