1. Chemical Composition
Table 3 -- Chemical Composition (Ladle Analysis)
| Type | Symbol | Chemical Composition (Ladle Analysis) a) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Mo | V | ||
| Type 1 | SNB 5 | ≥0.10 | ≤1.00 | ≤1.00 | ≤0.040 | ≤0.030 | 4.00 ~ 6.00 | 0.40 ~ 0.65 | – |
| Type 2 | SNB 7 | 0.38 ~ 0.48 | 0.20 ~ 0.35 | 0.75 ~ 1.00 | ≤0.040 | ≤0.040 | 0.80 ~ 1.10 | 0.15 ~ 0.25 | – |
| Type 3 | SNB16 | 0.36 ~ 0.44 | 0.20 ~ 0.35 | 0.45 ~ 0.70 | ≤0.040 | ≤0.040 | 0.80 ~ 1.15 | 0.50 ~ 0.65 | 0.25 ~ 0.35 |
Note a) Elements not specified in this table shall not be intentionally added to the steel, except for the purpose of completing the melt, unless agreed upon by both the supplier and the purchaser.
b) For SNB7, the upper limit of carbon content may be 0.50% when the diameter of the bolt material exceeds 90 mm.
b) For SNB7, the upper limit of carbon content may be 0.50% when the diameter of the bolt material exceeds 90 mm.
2. Mechanical properties of wire rod
Table 4 -- Mechanical Properties
| Type | Symbol | Diameter mm | Yield Strength N/mm² | Tensile Strength N/mm² | Elongation % | Reduction of Area % |
|---|---|---|---|---|---|---|
| Type 1 | SNB 5 | ≤100 | ≥550 | ≥690 | ≥16 | ≥50 |
| Type 2 | SNB 7 | ≤63 | ≥725 | ≥860 | ≥16 | ≥50 |
| 63<d≤100 | ≥655 | ≥800 | ≥16 | ≥50 | ||
| 100<d≤120 | ≥520 | ≥690 | ≥18 | ≥50 | ||
| Type 3 | SNB16 | ≤63 | ≥725 | ≥860 | ≥18 | ≥50 |
| 63<d≤100 | ≥655 | ≥760 | ≥17 | ≥50 | ||
| 100<d≤180 | ≥590 | ≥690 | ≥16 | ≥50 |
3. Dimensional Tolerances
Table 6 -- Dimensional Tolerances for Hot-Rolled Wire Rod
| Diameter | Diameter tolerance | Out-of-roundness |
|---|---|---|
| <15 | ±0.3 | <0.4 |
| 15<d≤25 | ±0.4 | <0.5 |
| 25<d≤32 | ±0.5 | <0.6 |
| 32<d≤50 | ±0.6 | <0.7 |
For diameters exceeding 50 mm, subject to agreement between supplier and purchaser.
Note a) Out-of-roundness refers to the difference between the maximum and minimum diameters measured on the same cross-section of the wire rod.
Note a) Out-of-roundness refers to the difference between the maximum and minimum diameters measured on the same cross-section of the wire rod.