Types of steel

According to the sulfur and phosphorus content in steel, it can be divided into:

1. Ordinary steel: phosphorus content ≤ 0.045%, sulfur content ≤ 0.055%; The phosphorus and sulfur content are both ≤ 0.050%.
2. High-quality steel: both phosphorus and sulfur content are ≤ 0.040%.
3. Special grade high-quality steel: phosphorus content ≤ 0.035%, sulfur content ≤ 0.030%.