This is a standard developed by the Deutsches Institut für Normung (DIN), which is the German Institute for Standardization. DIN standards are widely used in various industries to ensure compatibility and quality.

   - Scope: DIN 2391 is a standard for seamless precision steel tubes used in various mechanical and automotive engineering applications.

   - Part: The standard is divided into different parts (e.g., DIN 2391-1, DIN 2391-2, etc.), each dealing with specific aspects of seamless precision steel tubes.

 

   - Composition: ST37.4 is a low carbon steel grade, and its chemical composition may include elements such as carbon (C), manganese (Mn), phosphorus (P), sulfur (S), and other trace elements.

   - Mechanical Properties: The minimum yield strength for ST37.4 steel is 37 N/mm². Other mechanical properties, such as tensile strength and elongation, may also be specified.

   -This is a material grade within the DIN 2391 standard. ST37.4 refers to a specific type of steel. The "ST" stands for "steel" and the "37" refers to the minimum yield strength of the steel in N/mm² (in this case, 37 N/mm²). The ".4" indicates a particular level of precision in the manufacturing process.

Element	Percentage (%)
Carbon (C)	≤0.17
Manganese (Mn)	≤1.20
Silicon (Si)	≤0.55
Sulfur (S)	≤0.025
Phosphorus (P)	≤0.025

   - Cold Drawing Process: In the cold-drawn condition, the steel tube is processed by pulling it through a die to reduce its diameter and wall thickness. This process results in improved dimensional accuracy and surface finish.

   - Advantages: Cold drawing enhances the mechanical properties of the tube and produces a smoother surface, making it suitable for applications requiring precision.

 

   - Dimensional Accuracy: DIN 2391/C ST37.4 requires a high degree of dimensional accuracy to meet specific tolerances.

   - Surface Finish: Precision tubes often have a smooth surface finish, which is crucial in applications where rough surfaces could impact performance.

 

Property	Value
Tensile Strength	340-470 N/mm²
Yield Strength	≥235 N/mm²
Elongation (%)	≥25
Impact Strength	Not applicable

 

 

   - Automotive Industry: Precision steel tubes, including those meeting DIN 2391/C ST37.4, are commonly used in automotive components such as fuel injection systems, steering systems, and shock absorbers.

   - Mechanical Engineering: These tubes find applications in various mechanical engineering components where precision and reliability are essential.

 

 

   - Compliance: Tubes produced according to DIN 2391/C ST37.4 should adhere to the specific requirements outlined in the standard.

   - Testing: The tubes may undergo various tests, including dimensional checks, visual inspection, and mechanical property tests, to ensure they meet the specified standards.