EN31 Bearing Steel Guide 2025 | Properties & Applications

In 2025, as industries push for longer equipment life, higher wear resistance, and precision movement under high loads, EN31 bearing steel has emerged as a crucial material.

EN31 is a high-carbon alloy steel known for:
• Exceptional hardness
• Outstanding wear resistance
• High compressive strength
• Ability to maintain dimensional accuracy
• Long service life under rolling & sliding contact

It is one of the few engineering steels capable of handling extreme mechanical stress, making it ideal for bearings, gears, tools, shafts, fasteners, dies, and precision components.

This guide explains why EN31 is considered the ultimate bearing steel, how it compares to common grades, and where industries use it the most.

What Makes EN31 Special?

EN31 belongs to the family of high-carbon chromium-bearing steels. Its typical composition includes:

Carbon: 0.90–1.20%
Chromium: 1.0–1.6%
Manganese: 0.30–0.75%
Silicon: 0.10–0.35%

Why this matters:

High carbon → extreme hardness
Chromium → wear resistance + strength
Clean microstructure → precision movement

EN31 can be induction hardened or through hardened to reach hardness levels of 60–63 HRC, making it one of the hardest engineering steels available.

Mechanical Properties — Hardness Is Its Superpower

Property	EN31
Tensile Strength	850–1000 MPa
Hardness (Annealed)	200–250 HB
Hardness (Hardened)	60–63 HRC
Wear Resistance	Very High
Compressive Strength	High
Fatigue Strength	Excellent

Summary:

EN31 is designed for maximum surface hardness + wear resistance
Ideal for rolling, sliding, high-friction applications

EN31 vs EN24 vs EN19 vs EN8 – Quick Comparison

Grade	Strength	Hardness	Wear Resistance	Impact Toughness
EN8	Medium	Low–Medium	Medium	Medium
EN9	Medium–High	High	High	Moderate
EN19	High	High	High	High
EN24	Very High	Very High	High	Very High
EN31	High	Extremely High	Extremely High	Medium

✔ EN31 beats all others in hardness & wear resistance
✔ EN24 beats EN31 in toughness

Heat Treatment Performance

EN31 responds extremely well to heat treatment due to its high carbon content.

After heat treatment, EN31 becomes:

Ultra-hard (up to 63 HRC)
Highly wear resistant
Strong under compression
Resistant to micro-abrasion

Common heat treatments:

Hardening
Tempering
Case hardening
Induction hardening

This makes EN31 the most preferred material for bearings and precision tools.

Industrial Applications of EN31

Bearing Manufacturing

Ball bearings
Roller bearings
Needle bearings
Bearing races

Its hardness ensures long rolling life.

Gears & Transmission Components

Gearboxes
Motor systems
Industrial drivetrains

High wear resistance ensures smooth engagement.

Automotive Components

CV joints
Transmission rollers
Wear plates
Precision shafts

EN31 maintains dimensional accuracy under stress.

Tool & Die Manufacturing

Punches
Dies
Forming tools
Cutting tools

Its hardness ensures long service life.

Rolling & Sliding Components

Guide rails
Conveyor rollers
Machine slides
Linear motion parts

These components demand wear resistance & low surface deformation.

Heavy Machinery & Equipment

Hydraulic pistons
Industrial shafts
High-load pins
Bearing housings

Advantages of EN31 Steel

✔ Extreme hardness
✔ Exceptional wear resistance
✔ High fatigue strength
✔ Strong load-bearing capacity
✔ Excellent dimensional stability
✔ Long working life in frictional environments

EN31 is one of the few materials that can handle continuous rolling or sliding friction without deformation.

Limitations of EN31

⚠ Low impact toughness — not ideal for shock loads (Use EN24)
⚠ Difficult machinability after hardening
⚠ Poor weldability due to high carbon content
⚠ Low corrosion resistance — requires coating/lubrication

EN31 Material Selection Checklist

Choose EN31 if your application involves:

Continuous rolling motion
Sliding wear
Precision fits
High compressive load
Long-term durability
Tooling operations

Avoid EN31 if:

Shock loads are expected
Corrosion environment is severe
Welding is required

Conclusion

EN31 is truly the ultimate bearing and high-wear steel, designed for applications where hardness, wear resistance, and precision are critical.

While engineering steels like EN8, EN9, EN19, and EN24 serve general strength needs, EN31 stands alone for:
• Rolling contact fatigue • Abrasion resistance • High surface hardness • Long-term wear performance

For industries that cannot afford dimensional change or wear failure, EN31 delivers unmatched reliability.

Moksh Tubes & Fittings LLP supplies premium EN31 bars, rods, sheets, tubes, and machined components for global industrial applications.

FAQ's

Is EN31 good for shafts?

Yes — but only for precision or wear-critical shafts. For high-impact shafts, EN24 is better.

Is EN31 stronger than EN24?

EN31 is harder, but EN24 is tougher and stronger under shock loads.

Can EN31 be welded?

Not recommended — high carbon content leads to cracking.

What hardness does EN31 achieve after treatment?

Up to 60–63 HRC, one of the highest among engineering steels.

Where is EN31 used the most?

Bearings, rollers, dies, tools, gear components, and precision machinery.

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