EN8 Carbon Steel: Properties, Applications and Heat Treatment

EN8 carbon steel is a commonly used, unalloyed medium carbon steel that is known for its strength, toughness, and good machinability. It is also known by other names such as 080M40, 080A42, and 48C. EN8 is a popular choice for applications that require a strong and durable material, such as gears, crankshafts, shafts, and spindles. It is also commonly used in the manufacture of general engineering components, such as machinery parts, fasteners, and hydraulic fittings.8 Composition of EN8 Carbon Steel: The composition of EN8 carbon steel is specified by the British Standard BS 970-1955. The typical chemical composition of EN8 steel is:

• Carbon: 0.40 – 0.48%
• Manganese: 0.50 – 0.80%
• Phosphorus: 0.025% max
• Sulfur: 0.050% max
• Silicon: 0.10 – 0.35%

Properties of EN8 Carbon Steel: EN8 carbon steel has the following properties:

• Strength: EN8 carbon steel has a high tensile strength, making it ideal for applications where high strength is required.
• Toughness: EN8 carbon steel is known for its toughness, making it suitable for applications that are subjected to high levels of stress and impact.
• Machinability: EN8 carbon steel is relatively easy to machine, making it an ideal choice for manufacturing operations that require high levels of precision and accuracy.
• Hardness: EN8 carbon steel has a moderate level of hardness, making it resistant to wear and abrasion.
• Weldability: EN8 carbon steel is readily weldable and can be easily joined using conventional welding methods.

Applications of EN8 Carbon Steel: EN8 carbon steel has a wide range of applications due to its combination of strength, toughness, and machinability. Some of the common applications of EN8 carbon steel include:

• Gears: EN8 carbon steel is commonly used in the manufacture of gears, such as spur gears, bevel gears, and helical gears.
• Crankshafts: EN8 carbon steel is used in the manufacture of crankshafts, which are critical components in internal combustion engines.
• Shafts: EN8 carbon steel is used in the manufacture of shafts, which are used in a wide range of applications, including conveyor systems, pumps, and motors.
• Spindles: EN8 carbon steel is used in the manufacture of spindles, which are used in a variety of machines, such as lathes, milling machines, and drilling machines.
• Hydraulic fittings: EN8 carbon steel is used in the manufacture of hydraulic fittings, which are used in high-pressure fluid power systems.
• Machinery parts: EN8 carbon steel is commonly used in the manufacture of machinery parts, such as gears, bearings, and couplings.
• Fasteners: EN8 carbon steel is used in the manufacture of fasteners, such as screws, bolts, and nuts.

Heat Treatment of EN8 Carbon Steel: EN8 carbon steel can be heat treated to achieve a desired level of strength and hardness. The most common heat treatment process for EN8 carbon steel is normalizing, which is a process that involves heating the steel to a temperature above its critical temperature, holding it at that temperature for a specific time, and then cooling it in still air. Normalizing results in a microstructure that is homogeneous and uniform, and it

Frequently asked questions

What is the equivalent of EN8?

080M40 (BS 970), C40 (EN 10083) and AISI/SAE 1040 are close equivalents.

Can EN8 be hardened?

Yes. It can be through-hardened and tempered or surface hardened by flame or induction to about 50–55 HRC.

What is EN8 used for?

Shafts, axles, spindles, studs, bolts, gears and general engineering parts.