Mild Steel grades, such as SAE 1018 and A36, exhibit a tensile strength ranging from 400 to 570 MPa and a yield strength between 235 and 480 MPa. They possess a hardness of 120 to 248 Brinell and an elongation of 15 to 25%, indicating good ductility. Impact toughness values typically range from 25 to 50 J, making these steels suitable for a variety of structural applications. Their low carbon content enhances weldability and formability, ideal for construction and manufacturing.
Specifications :
| Grade | Composition | Tensile Strength (MPa) | Yield Strength (MPa) | Hardness (Brinell) | Elongation (%) | Applications |
|---|---|---|---|---|---|---|
| SAE 1018 | C: 0.15-0.20%, Mn: 0.60-0.90% | 440 – 570 | 370 – 480 | 126 – 192 | 15 – 20 | General machining, automotive components |
| SAE 1020 | C: 0.18-0.23%, Mn: 0.30-0.60% | 400 – 540 | 350 – 450 | 126 – 192 | 15 – 25 | Structural components, shafts, frames |
| SAE 1040 | C: 0.37-0.44%, Mn: 0.60-0.90% | 570 – 740 | 410 – 580 | 207 – 248 | 10 – 15 | High-strength applications, gears |
| A36 | C: 0.26-0.29%, Mn: 0.60-0.90% | 400 – 550 | 250 – 400 | 120 – 150 | 20 – 25 | Construction, bridges, general structures |
| S235JR | C: ≤0.17%, Mn: 1.0% | 370 – 510 | 235 | 120 – 160 | 20 | Structural steel, fabrication, engineering |
| S275JR | C: ≤0.20%, Mn: 1.0% | 370 – 510 | 275 | 130 – 160 | 20 | Construction, bridges, structural applications |
Chemical Composition :
| Grade | Carbon (C) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) |
|---|---|---|---|---|---|
| SAE 1018 | 0.15-0.20% | 0.60-0.90% | ≤ 0.10% | ≤ 0.04% | ≤ 0.05% |
| SAE 1020 | 0.18-0.23% | 0.30-0.60% | ≤ 0.10% | ≤ 0.04% | ≤ 0.05% |
| SAE 1040 | 0.37-0.44% | 0.60-0.90% | ≤ 0.10% | ≤ 0.04% | ≤ 0.05% |
| A36 | 0.26-0.29% | 0.60-0.90% | ≤ 0.40% | ≤ 0.04% | ≤ 0.05% |
| S235JR | ≤ 0.17% | 1.0% | ≤ 0.30% | ≤ 0.04% | ≤ 0.05% |
| S275JR | ≤ 0.20% | 1.0% | ≤ 0.30% | ≤ 0.04% | ≤ 0.05% |
Mechanical Properties :
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Hardness (Brinell) | Elongation (%) | Impact Toughness (J) |
|---|---|---|---|---|---|
| SAE 1018 | 440 – 570 | 370 – 480 | 126 – 192 | 15 – 20 | 30 – 50 |
| SAE 1020 | 400 – 540 | 350 – 450 | 126 – 192 | 15 – 25 | 30 – 50 |
| SAE 1040 | 570 – 740 | 410 – 580 | 207 – 248 | 10 – 15 | 25 – 40 |
| A36 | 400 – 550 | 250 – 400 | 120 – 150 | 20 – 25 | 27 – 35 |
| S235JR | 370 – 510 | 235 | 120 – 160 | 20 | 27 – 35 |
| S275JR | 370 – 510 | 275 | 130 – 160 | 20 | 27 – 35 |
