JIS G 3112 is the Japanese Industrial Standard for Steel Bars for Concrete Reinforcement. Here’s a detailed breakdown:
Standard Classification Table:
| Grade Symbol | Yield Point (N/mm²) | Tensile Strength (N/mm²) | Elongation (%) |
|---|---|---|---|
| SD295A | ≥295 | ≥440 | ≥20 |
| SD345 | ≥345 | ≥490 | ≥18 |
| SD390 | ≥390 | ≥560 | ≥16 |
| SD490 | ≥490 | ≥620 | ≥14 |
Nominal Diameter Specifications:
| Size (D) | Nominal Diameter (mm) | Cross-sectional Area (mm²) | Mass per Meter (kg/m) |
|---|---|---|---|
| D10 | 10 | 71.3 | 0.560 |
| D13 | 13 | 126.7 | 0.995 |
| D16 | 16 | 198.6 | 1.56 |
| D19 | 19 | 286.5 | 2.25 |
| D22 | 22 | 387.1 | 3.04 |
| D25 | 25 | 506.7 | 3.98 |
| D29 | 29 | 642.4 | 5.04 |
| D32 | 32 | 794.2 | 6.23 |
| D35 | 35 | 956.6 | 7.51 |
| D38 | 38 | 1140 | 8.95 |
| D41 | 41 | 1340 | 10.5 |
Chemical Composition Requirements (maximum %):
| Grade | C | Si | Mn | P | S |
|---|---|---|---|---|---|
| SD295A | 0.27 | 0.55 | 1.60 | 0.040 | 0.040 |
| SD345 | 0.27 | 0.55 | 1.60 | 0.040 | 0.040 |
| SD390 | 0.28 | 0.55 | 1.60 | 0.040 | 0.040 |
| SD490 | 0.30 | 0.55 | 1.60 | 0.040 | 0.040 |
Key Requirements:
- Bars must be marked to indicate manufacturer, size, and grade
- Surface deformations must meet specific pattern requirements
- Bend test requirements vary by bar size and grade
- Weldability requirements for specific grades
