Steel grade C55

Steel grade C55 is an unalloyed steel with higher carbon content. It is characterized by good mechanical strength and moderate machinability. Due to its higher carbon content, it is more demanding during machining than steels with lower carbon content. It is recommended to use tools with high wear resistance. Elevated carbon concentration is beneficial for carrying out hardening, which allows for high surface hardness and wear resistance. Thanks to its properties, this steel is widely used in the production of components subjected to medium and heavy loads, such as springs, shafts and tools of moderate durability.

In order to improve mechanical properties, C55 steel can be subjected to heat treatment operations such as:

• 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 C55 chemical composition

Steel C55 mechanical properties

C55 steel application

• C55 steel is widely used in the manufacture of components requiring good strength and wear resistance. Typical applications include:
• Springs and springs, operating under low loads
• Shafts and axles subjected to mechanical and dynamic loads
• Gears
• Bushings and rings
• Knives and hand tools
• Mechanical components used in agricultural, construction and industrial machinery

Steel C55 designations

Steel C55 standards

PN-EN 10083, PN-EN 683