Introduction to STKM18A: Properties, Applications, and Chemical Composition

STKM18A is a steel pipe material specified under Japan's JIS G 3445 standard, widely used for mechanical structures. Its equivalent standards include ASTM A513 Type 5, ASTM A519 Grade 1010 or Grade 1018, and DIN 2391 St 35 or St 37. Manufactured through the cold drawing process, this steel offers high precision and excellent surface quality. STKM18A provides moderate strength and workability, making it suitable for various mechanical and industrial applications.

- Chemical Composition

Carbon (C): ≤ 0.12%

Manganese (Mn): 0.30–0.60%

Phosphorus (P): ≤ 0.040%

Sulfur (S): ≤ 0.040%

- Mechanical Properties

Yield Strength: ≥ 275 MPa

Tensile Strength: ≥ 440 MPa

Elongation: ≥ 20% (based on standard gauge length)

Hardness: ≤ HRB 70

- Features and Characteristics

Strength and Toughness:

STKM18A provides moderate strength and toughness, making it suitable for mechanical structures. It ensures uniform mechanical properties and high reliability.

Workability:

The cold drawing process results in a smooth surface and high precision, allowing for easy processing such as cutting, bending, and welding.

Weldability:

Exceptional weldability enables seamless connections using various welding methods.

Durability:

STKM18A provides adequate durability in general usage environments, ensuring long service life in mechanical applications.

- Applications

Automotive Components:

Used in suspension parts, engine components, frame elements, and other automotive applications.

Industrial Machinery:

Applied in robot arms, machinery frames, and various industrial equipment components.

Construction and Structures:

Ideal for architectural structures, supports, and pipelines.

Furniture and Interior:

Used in furniture frames, chairs, desks, and other products requiring structural stability.

- Comparison with STKM17A

STKM18A offers slightly higher strength than STKM17A, though with marginally lower elongation. This makes STKM18A preferable for applications requiring greater structural integrity.

- Conclusion

STKM18A is a crucial material widely used in demanding mechanical components and structures due to its excellent mechanical properties and processability.