Bar Sizes & Standard Hooks
Bar number = nominal diameter in 1/8-inch units (e.g. a #8 bar is 8/8 = 1.000 in nominal diameter). #14 and #18 bars are not simple multiples of 1/8 in and are typically used only in columns.
Grade / Yield Strength
| Grade | Min. Yield (ksi) | Min. Tensile (ksi) | Typical Use |
|---|---|---|---|
| Grade 40 | 40 | 60 | Light residential slabs/footings, stirrups — increasingly uncommon |
| Grade 60 | 60 | 90 | Default grade for most structural/commercial reinforced concrete |
| Grade 75 | 75 | 100 | Heavy structural members, high-rise columns |
| Grade 80 | 80 | 105 | High-strength applications, congested reinforcement |
| A706 Grade 60/80 | 60 / 80 | 80 / 100 | Low-alloy, controlled chemistry — required where bars are welded or in seismic detailing |
Minimum Concrete Cover
Cover is measured from the concrete surface to the outermost surface of the steel (including stirrups/ties, if they're the outermost bar).