EN36 vs 16MnCr5 vs 8620: Which Steel Is Best for Gears?
If you’ve ever worked on gear design or material selection, you know this:
👉 The wrong steel choice doesn’t fail immediately — it fails under load, over time.
That’s why selecting between EN36, 16MnCr5, and AISI 8620 is not just about properties — it’s about performance in real-world conditions.
Why Gear Steel Selection Matters
Gears operate under:
High contact stress
Continuous friction
Repeated loading cycles
To handle this, engineers rely on case-hardening steels, which provide a combination of:
Hard outer surface → wear resistance
Tough inner core → shock absorption
This balance is critical for long service life.
EN36 Steel – Maximum Strength & Fatigue Resistance
EN36 is a nickel-chromium alloy steel designed for high-performance applications.
Key advantages:
Deep case hardening capability
Excellent fatigue resistance
High core strength
Studies show EN36 can provide significantly higher safety factors and wear resistance compared to 8620 in gear applications
Best for:
Aerospace gears
Heavy-duty automotive systems
High-load applications
👉 Downside: Higher cost
16MnCr5 – Balanced & Cost-Effective
16MnCr5 is one of the most widely used carburizing steels in Europe.
Key properties:
High surface hardness
Good wear resistance
Balanced strength and toughness
It offers an excellent combination of wear-resistant surface and ductile core, making it ideal for gears and shafts
Best for:
Automotive gears
Transmission systems
Mass production
👉 Advantage: Cost-performance balance
AISI 8620 – Tough & Versatile
8620 is a globally popular case-hardening steel.
Key features:
Excellent toughness (nickel + molybdenum)
Good machinability
Reliable performance
The alloy composition improves hardenability and toughness, making it ideal for heavy-duty applications
Best for:
Differential gears
Shafts and pinions
Heavy machinery
👉 Advantage: Cost-effective + tough core
Quick Comparison
Property | EN36 | 16MnCr5 | 8620 |
Wear Resistance | Very High | High | High |
Core Toughness | High | Moderate | Very High |
Cost | High | Medium | Low |
Best Use | Aerospace / Heavy Duty | Automotive | General Engineering |
Which Steel Should You Choose?
There is no “best” steel — only the right steel for your application.
Choose EN36 → for maximum strength and fatigue resistance
Choose 16MnCr5 → for balanced performance and cost
Choose 8620 → for toughness and versatility
Detailed Technical Guide
If you want a deeper breakdown (properties, heat treatment, applications), this guide explains everything clearly:
👉 https://niftyalloys.com/blogs/en36-vs-16mncr5-vs-8620-gears
Final Thoughts
Material selection is one of the most critical decisions in gear design.
Even small differences in alloy composition can lead to major differences in:
Performance
Wear life
Maintenance cost
Understanding EN36, 16MnCr5, and 8620 helps you make smarter engineering decisions — not just theoretical ones.