Steel grade C55E

Steel grade C55E is a non-alloyed tempering steel with a higher carbon content. This chemical composition allows for high hardness and mechanical strength after appropriate heat treatment. The E designation indicates reduced sulfur and phosphorus content, which improves the homogeneity of the structure and purity of the alloy. In addition, the reduced content of S and P improves the fracture toughness and fatigue strength of the material, especially during operation under varying loads.

C55E steel achieves high surface hardness due to heat treatment, while maintaining adequate core ductility. The C55E grade is characterized by moderate machinability. Machining, such as turning, milling and drilling, requires tools with high wear resistance. Due to its high carbon content, the steel requires appropriate selection of cutting parameters. It is a structural material of high strength and hardness, ideal for the manufacture of parts subjected to high mechanical loads.

Thanks to its mechanical properties, C55E steel is widely used in the engineering, automotive and toolmaking industries.

C55E steel can be subjected to heat treatment operations, including:

• Hardening, heating to 820-860°C, cooling in water or oil, which leads to surface hardening and increased wear resistance.
• Tempering, which is conducted at 150-200°C to reduce stresses and improve fracture resistance.
• Normalizing, is conducted at 840-880°C to achieve a homogeneous structure and improve machinability.
• Carburizing (optional), which is performed for parts requiring a hard surface while maintaining a ductile core.

Steel C55E chemical composition

Steel C55E mechanical properties

C55E steel application

C55E steel is used in the manufacture of components subjected to high mechanical and dynamic loads. Typical applications include:

• Springs, requiring high hardness and flexibility.
• Shafts and axles, used in drive systems and industrial machinery
• Gears, bearings, as components in heavy-duty mechanical transmission systems
• Pins and bushings, as components subject to friction and wear
• Knives and tools, in the manufacture of hand and technical tools
• Chains and bolts
• Mechanical parts, in agricultural, construction and industrial machinery.

Steel C55E designations

Steel C55E standards

PN-EN 10083, PN-EN 683