St37 and St52 Steel
St37 and St52 steels are widely used in industries, particularly in machine building, construction, steel profile manufacturing, and more. In the following, we will examine the mechanical properties and chemical compositions of each.
St37 Steel
This type of steel is classified as one of the most widely used steels and belongs to the group of construction steels (mild steel). St37 steel is a non-alloyed steel. Due to its features such as high strength and excellent weldability, it is widely used in industries such as machine building, parts manufacturing, construction, and the production of steel profiles like angles, I-beams, channels, etc. The “St” at the beginning of this steel’s name stands for “Steel,” and its naming is based on the DIN 17006 standard. The number used in the naming of this steel represents its ultimate tensile strength in kilograms per millimeter. Accordingly, St37 steel has a tensile strength of 37 kilograms per millimeter.
Below is a table showing the mechanical properties and chemical composition of St37 steel.
Chemical Composition Percentage:
| Carbon (C) | Magnesium | Silicon (Si) | Phosphorus (P) | Sulfur (S) | Nitrogen | Copper (Cu) |
| 0.19 |
1.5 |
– | 0.045 | 0.014 | 0.045 | 0.6 |
Mechanical Properties
| Tensile Strength (MPa) | Minimum Yield Strength (MPa) |
| 510_360 | 235 |
The values stated above are for steel in sheet form. The yield strength and carbon content in the chemical composition are for a thickness of 16 mm or less, and the tensile strength is obtained for a thickness of less than 3 mm.
Steel St52
This steel has extensive applications in the machinery manufacturing and parts manufacturing industries. The reason for this is the presence of phosphorus and sulfur elements in its chemical composition, which contribute to the favorable machinability and chip formation properties. This steel also demonstrates significant strength at high temperatures. The presence of magnesium (manganese) in this steel increases its hardness. Similar to St37 steel, the ultimate tensile strength of St52 steel is equivalent to 52 kg per millimeter.
Below are the mechanical properties and chemical composition of St52 steel.
Percentage of chemical compositions
| Carbon | Magnesium | Silicon | Phosphorus | Nitrogen | Sulfur |
| 0.24 | 1.6 | 0.55 | 0.045 | 0.014 | 0.045 |
Mechanical Properties
| Tensile Strength (MPa) | Minimum Yield Stress (MPa) |
| 490-630 | 315-355 |
