SAE 52100 bearing steel

Introduction

We manufacture forging ingots, billets, and blooms in high-carbon chromium steel specifically for SAE 52100, designed for ultra-high hardness, exceptional wear resistance, and superior fatigue performance in precision engineering applications. SAE 52100 is a high carbon, chromium alloy steel renowned as the industry standard for bearing applications. It is engineered to deliver extremely high hardness, excellent contact fatigue strength, and outstanding dimensional stability after heat treatment. The high carbon content enables very high hardness, while chromium improves hardenability, wear resistance, and fatigue life. SAE 52100 exhibits a fine, uniform microstructure when properly heat treated, making it ideal for high-precision and high-speed components. This grade provides consistent performance, long service life, and reliability for critical rotating and load-bearing applications.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.98 – 1.10	Provides very high hardness and wear resistance
Manganese (mn)	0.25 – 0.45	Improves hardenability and strength
Silicon (si)	0.15 – 0.35	Increases strength and elasticity
Chromium (cr)	1.30 – 1.60	Enhances hardenability, wear, and fatigue resistance
Phosphorus (p)	Max 0.025	Impurity; controlled to maintain toughness
Sulphur (s)	Max 0.025	Impurity; controlled for machinability

Mechanical properties (typical – quenched & tempered)

• hardness: 60 – 66 hrc
• tensile strength: very high (application dependent)
• impact toughness: moderate
• wear resistance: excellent
• contact fatigue strength: outstanding
(properties may vary depending on section size, microstructure, and heat treatment conditions)

Heat treatment

• spheroidize annealing: used to improve machinability and prepare for hardening.
• hardening: heating to approximately 830 – 860°c followed by oil quenching to achieve a fully martensitic structure.
• tempering: low-temperature tempering to relieve internal stresses while maintaining very high hardness.
Precise heat treatment control is critical to achieve optimal bearing performance and dimensional stability.

Key features and benefits

• very high hardness and wear resistance
• exceptional contact fatigue life
• excellent dimensional stability
• fine and uniform microstructure
• high load-carrying capacity
• ideal for precision and high-speed applications

Typical applications

• ball, roller, and tapered bearings
• bearing races and rings
• precision shafts and spindles
• rollers and needle
• high-wear machine components
• tooling and dies (special applications)

Equivalent steel grades

SAE 52100 has several international equivalents, including:

• en 100cr6 – european standard
• din 100cr6 – german standard
• jis suj2 – japanese standard
• is 5517 – 100cr6 type – indian standard

Why choose SAE 52100 for your application?

SAE 52100 is the benchmark material for bearing and high-wear applications. Its combination of very high hardness, superior fatigue resistance, and excellent dimensional stability ensures long service life and reliable performance in critical, high-precision components operating under continuous load and speed.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
SAE 52100	0.98 – 1.10	Ball and roller bearings	Hardening & tempering	Industry standard bearing steel
100cr6	0.95 – 1.10	Bearing races and rollers	Hardening & tempering	European equivalent
Suj2	0.95 – 1.10	Precision bearings	Hardening & tempering	Japanese equivalent

Summary

SAE 52100 is a premium high-carbon chromium bearing steel optimized for hardened and precision applications. It delivers exceptional wear resistance, outstanding fatigue life, and consistent performance for the most demanding rotating and load-bearing components.