EN31 is a high-carbon, high-chromium alloy steel known for its exceptional hardness, wear resistance, and strength after heat treatment. It is one of the most widely used steels for bearing applications, precision components, and wear-critical machine parts. EN31 can be hardened to very high levels (up to 60–66 HRC) while maintaining good compressive strength, making it suitable for parts subjected to rolling contact, friction, and high surface wear.

Key Properties of EN31

1. Very High Hardness

After proper heat treatment (quenching + tempering), EN31 achieves:
a. 60–66 HRC surface hardness
b. High wear resistance
c. Excellent compressive strength

2. Excellent Wear Resistance

Ideal for rolling, sliding, and impact wear applications.

3. High Strength & Fatigue Resistance

Suitable for high-load rotating parts like bearings, cams, and rollers.

4. Moderate Toughness

Better than plain carbon steels but not as high as alloy steels like EN19 or EN24.

5. Dimensional Stability

Maintains accuracy after heat treatment, important for bearing and tool components.

6. Medium Machinability

Machinability is good in annealed condition; difficult after hardening.

7. Poor Weldability

Due to high carbon content, EN31 is generally not recommended for welding.

Typical Applications of EN31

EN31 is widely used in automotive, engineering, machinery, tool room, bearing manufacturing, and textile industry.

Typical applications include:
1. Ball bearings, roller bearings & bearing races
2. Needle rollers & bushes
3. Gears & pinions
4. High-wear automotive parts
5. Shafts, axles & spindles
6. Precision measuring tools
7. Punches, dies & forming rolls
8. Tappets, cams & cam followers
9. Knives, blades & cutting tools
10. Ball screws & linear motion components
11. Press tools & machine tool parts

Heat Treatment Capabilities

1. Annealed: 200–250 Brinell
2. Hardened & Tempered: 58–66 HRC
3. Core Toughness: Moderate
4. Case Hardening: Possible if required
EN31 offers one of the best combinations of hardness + wear resistance in commercial engineering steels.

Why Choose EN31?

Choose EN31 when your application requires:
1. Extremely high hardness
2. Superior wear resistance
3. High load-bearing capacity
4. Dimensional accuracy
5. Long service life in frictional components
It is the standard grade for bearings and high-wear tools.