SkillsUSA Carpentry Practice Test

Metric rebar is sized by its diameter, and that diameter is expressed in millimeters. Using millimeters allows precise, standard measurements for the thickness of the reinforcing bar, with common sizes like 6 mm, 8 mm, 10 mm, 12 mm, and so on. Lengths of rebar, on the other hand, are typically given in meters, but the measurement that defines the bar’s size is the diameter in millimeters. Inches would apply to imperial units, not metric, and centimeters are less practical for the common rebar sizes.