#7 Rebar (7/8 Inch Reinforcing Bar)
Authoritative dimensional properties, unit weight, cross-sectional area, spacing tables, standard hook geometries, and ACI 318-19 tension development length for structural concrete design.
| Bar Designation | #7 | Code Standard | ASTM A615 / A706 |
| Nominal Diameter (db) | 0.875 in | Metric Diameter | 22.23 mm |
| Cross-Sectional Area (Ab) | 0.6 in² | Metric Area | 387 mm² |
| Linear Weight | 2.044 lb/ft | Metric Mass | 3.042 kg/m |
| Nominal Perimeter | 2.749 in | Metric Perimeter | 69.8 mm |
| Minimum Clear Spacing | max(1.0″, 0.875″) | ACI Provision | ACI 318-19 §25.2.1 |
| Hook Type | Min. Inside Bend Pin | Extension Length (US) | Extension Length (SI) |
|---|---|---|---|
| 90° Standard Hook | 5.25″ (133 mm) | 10.5″ (12db) | 267 mm |
| 180° Standard Hook | 5.25″ (133 mm) | 3.5″ (max(4db, 2.5″)) | 89 mm |
Common Structural Applications
- ›Heavy commercial building beams and transfer girders
- ›Building columns subjected to combined axial and moderate bending
- ›Deep foundation pile caps and drilled shaft vertical rebar cages
- ›Heavily loaded industrial floor slabs
Exceeds #6 size; size factor ψs reverts to 1.0 in ACI 318 development length. Lap splice lengths increase noticeably. Requires power bender in fabrication yard.
#7 Rebar Spacing Table (As / Unit Width)
Area of longitudinal reinforcement provided for slabs, walls, and footing mats at given on-center spacings.
| 3″ o.c. | 4″ o.c. | 5″ o.c. | 6″ o.c. | 7″ o.c. | 8″ o.c. | 9″ o.c. | 10″ o.c. | 12″ o.c. | 14″ o.c. | 16″ o.c. | 18″ o.c. |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2.400in²/ft | 1.800in²/ft | 1.440in²/ft | 1.200in²/ft | 1.029in²/ft | 0.900in²/ft | 0.800in²/ft | 0.720in²/ft | 0.600in²/ft | 0.514in²/ft | 0.450in²/ft | 0.400in²/ft |
ACI 318-19 Tension Development Length (ld)
Calculated using ACI 318-19 Section 25.4.2.3 simplified method for Grade 60 (420 MPa) deformed bars in normal-weight concrete with clear spacing ≥ db and clear cover ≥ db.
| Concrete Strength (f'c) | Bottom Bars (ld) [ψt = 1.0] | Top Bars (ld) [ψt = 1.3] | Governing Provision | Minimum Limit |
|---|---|---|---|---|
| 3,000 psi | 47.9″(1217 mm) | 62.3″(1582 mm) | ACI 318-19 Table 25.4.2.3 | ld ≥ 12″ (300 mm) |
| 4,000 psi | 41.5″(1054 mm) | 54″(1372 mm) | ACI 318-19 Table 25.4.2.3 | ld ≥ 12″ (300 mm) |
| 5,000 psi | 37.1″(942 mm) | 48.3″(1227 mm) | ACI 318-19 Table 25.4.2.3 | ld ≥ 12″ (300 mm) |
| 6,000 psi | 33.9″(861 mm) | 44.1″(1120 mm) | ACI 318-19 Table 25.4.2.3 | ld ≥ 12″ (300 mm) |
Design Reinforcement with #7 in AXIS
Run instant ACI 318-19 beam flexure, shear stirrup spacing, column P-M interaction, and development length checks with full KaTeX step-by-step audit logs.