EN 100Cr6 Bearing Steel: Properties, Applications, and Manufacturing Guide

If you work in industries like automotive, aerospace, or industrial machinery, you’ve likely heard of bearing steel. Among the most widely used options is EN 100Cr6 bearing steel—a high-carbon, chromium-alloyed steel designed for components that need exceptional wear resistance and fatigue strength. This guide breaks down everything you need to know about EN 100Cr6, from its core properties to real-world uses and how it compares to other materials.

1. Material Properties of EN 100Cr6 Bearing Steel

Understanding EN 100Cr6 starts with its properties, which make it ideal for high-stress bearing applications. Below is a detailed breakdown of its chemical, physical, mechanical, and other key properties.

1.1 Chemical Composition

EN 100Cr6’s composition is tightly regulated to ensure consistency and performance. The table below shows its typical chemical makeup (per EN 10083-3 standards):

1.2 Physical Properties

These properties define how EN 100Cr6 behaves under physical conditions like temperature and magnetic fields:

• Density: 7.85 g/cm³ (same as most carbon steels)
• Melting Point: 1,420 – 1,460 °C (2,588 – 2,660 °F)
• Thermal Conductivity: 46.5 W/(m·K) at 20 °C (room temperature)
• Coefficient of Thermal Expansion: 11.5 × 10⁻⁶/°C (from 20 – 100 °C)
• Magnetic Properties: Ferromagnetic (attracts magnets), which is useful for sorting and inspection.

1.3 Mechanical Properties

Mechanical properties determine how EN 100Cr6 performs under force. These values are measured after standard heat treatment (quenching and tempering):

1.4 Other Properties

Two critical properties make EN 100Cr6 stand out for bearings:

• Wear Resistance: Its high carbon and chromium content form hard carbides, reducing wear from rolling or sliding contact.
• Fatigue Resistance: It can withstand millions of load cycles without failing—essential for bearings in cars or industrial machines.
• Corrosion Resistance: Moderate (not as good as stainless steel). It needs coatings (like zinc plating) for wet or harsh environments.
• Hardenability: Easy to heat treat to high hardness across thick sections, ensuring uniform performance in large components.

2. Applications of EN 100Cr6 Bearing Steel

EN 100Cr6’s properties make it perfect for components that face repeated stress and wear. Here are its most common uses:

• Bearings: The #1 use—including ball bearings, roller bearings, and needle bearings. These are found in car engines, electric motors, and bicycles.
• Rolling Elements: The balls, rollers, or needles inside bearings rely on EN 100Cr6’s wear resistance.
• Races: The inner/outer rings of bearings (where rolling elements move) are often made from EN 100Cr6.
• Automotive Components: Beyond bearings, it’s used for camshafts, valve lifters, and gearbox parts—all of which need high durability.
• Industrial Machinery: Gearboxes, conveyors, and pumps use EN 100Cr6 parts to handle heavy loads and long operating hours.
• Aerospace Components: Small bearings in aircraft landing gear or engine accessories (where weight and reliability matter).
• Medical Devices: Precision bearings in MRI machines or surgical tools (thanks to its magnetic properties and strength).

3. Manufacturing Techniques for EN 100Cr6

Producing EN 100Cr6 requires careful steps to ensure quality. Here’s the typical process:

1. Steelmaking:

• Most EN 100Cr6 is made using an Electric Arc Furnace (EAF) or Basic Oxygen Furnace (BOF). EAF is more common for recycling scrap steel, while BOF uses iron ore. The goal is to melt raw materials and adjust the chemical composition to meet EN standards.

2. Rolling:

• After steelmaking, the metal is Hot Rolled into billets or bars (at 1,100 – 1,200 °C) to shape it. For precision parts, it’s then Cold Rolled (at room temperature) to improve surface finish and dimensional accuracy.

3. Heat Treatment:

• This step is critical for EN 100Cr6’s performance:
• Quenching: Heating the steel to 820 – 860 °C, then rapidly cooling it in oil or water to harden it.
• Tempering: Reheating to 150 – 200 °C to reduce brittleness while keeping high hardness.
• Carburizing: Sometimes used for parts needing a hard outer layer (e.g., gear teeth) — heating in a carbon-rich atmosphere to add carbon to the surface.

4. Machining:

• After heat treatment, parts are machined to final shapes using Turning (for cylindrical parts like bearing races) or Grinding (for ultra-smooth surfaces, critical for bearing performance).

5. Quality Control:

• Inspections include:
• Chemical analysis (to check element content).
• Hardness testing (using Rockwell or Vickers machines).
• Non-destructive testing (like ultrasonic testing) to find internal cracks.
• Dimensional checks (using calipers or CNC measuring tools) to ensure parts fit.

4. Case Studies: EN 100Cr6 in Action

Real-world examples show how EN 100Cr6 solves industry problems.

Case Study 1: Automotive Bearing Failure Analysis

A car manufacturer noticed frequent bearing failures in their SUV engines. After testing, engineers found the original bearings used a low-grade steel that wore out after 50,000 km. They switched to EN 100Cr6 bearings, which had higher wear resistance. Post-switch, failure rates dropped by 80%, and bearing life extended to 150,000 km.

Case Study 2: High-Speed Train Bearing Optimization

A railway company needed bearings for high-speed trains (up to 300 km/h) that could handle vibration and heat. They chose EN 100Cr6 for its fatigue resistance and worked with manufacturers to add a ceramic coating (for extra heat protection). The new bearings lasted 2x longer than the previous stainless steel ones, cutting maintenance costs by 35%.

5. EN 100Cr6 vs. Other Bearing Materials

How does EN 100Cr6 stack up against other common options? The table below compares key factors:

Yigu Technology’s Perspective on EN 100Cr6

At Yigu Technology, we’ve seen EN 100Cr6 become a cornerstone for our clients in automotive and industrial machinery. Its balance of wear resistance, fatigue strength, and cost-effectiveness makes it unmatched for most bearing applications. We often recommend EN 100Cr6 for clients looking to cut maintenance costs—paired with our precision machining, it delivers parts that last 15-20% longer than standard steel options. For harsh environments, we also offer custom coatings (like zinc or ceramic) to boost EN 100Cr6’s corrosion resistance, meeting even the strictest industry needs.

FAQ About EN 100Cr6 Bearing Steel

1. Can EN 100Cr6 be used in wet or corrosive environments?

EN 100Cr6 has moderate corrosion resistance. For wet or harsh environments (like marine or food processing), it needs a protective coating (e.g., zinc plating or chrome plating) to prevent rust.

2. What heat treatment is required for EN 100Cr6 bearings?

The standard heat treatment is quenching (820–860 °C, rapid cooling) followed by tempering (150–200 °C). This process achieves the high hardness (60–64 HRC) and fatigue resistance needed for bearings.

3. How does EN 100Cr6 compare to AISI 52100?

They are nearly identical! EN 100Cr6 is the European standard, while AISI 52100 is the U.S. standard. Both have the same carbon (0.95–1.05%) and chromium (1.30–1.65%) content, so they can be used interchangeably in most applications.