En353 alloy steel

Introduction

We manufacture forging ingots, billets, and blooms in alloy steel specifically for En353, tailored for heavy-duty case hardening applications.

En353 is a low carbon nickel–chromium alloy steel developed for components requiring an extremely hard, wear-resistant surface combined with a very tough and shock-resistant core. It is widely used for highly stressed automotive and engineering components subjected to heavy loads, impact, and continuous wear.

The higher nickel content provides superior core toughness and fatigue resistance, while chromium improves hardenability and wear resistance after carburizing. En353 offers good machinability in the annealed condition and maintains dimensional stability after heat treatment, making it suitable for forging and precision machining processes.

This steel delivers excellent surface durability, core strength, and long service life in demanding industrial applications.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.10 – 0.20	Ensures tough and ductile core
Manganese (mn)	0.40 – 0.70	Improves hardenability and strength
Silicon (si)	Max 0.35	Increases strength
Nickel (ni)	3.25 – 3.75	Improves toughness and fatigue resistance
Chromium (cr)	1.20 – 1.60	Improves hardenability and wear resistance
Phosphorus (p)	Max 0.035	Impurity; controlled for toughness
Sulphur (s)	Max 0.035	Impurity; controlled for machinability

Mechanical properties (typical, depending on condition & heat treatment)

• Core tensile strength: 800 – 1000 MPa
• Core yield strength: 550 – 750 MPa
• Surface hardness (carburized): 58 – 62 HRC
• Core hardness: 200 – 240 HB
• Impact toughness: Very high
• Fatigue resistance: Excellent

Heat treatment

• annealing: improves machinability before carburizing.
• carburizing: introduces carbon at high temperature to achieve a hard, wear-resistant surface.
• quenching: rapid cooling to obtain a hard martensitic case.
• tempering: relieves internal stresses while maintaining surface hardness and core toughness.

The heat treatment cycle can be adjusted based on required case depth and service conditions.

Key features and benefits

• excellent case hardening response: very hard surface with tough core
• extremely high impact and fatigue resistance
• superior wear resistance for long service life
• good machinability in annealed condition
• dimensional stability after heat treatment
• suitable for forging and machining processes

Typical applications

• heavy-duty gears and pinions
• transmission and differential components
• camshafts and crankshaft gears
• automotive and tractor parts
• critical engineering components subjected to heavy loads

Equivalent steel grades

• En353 has several international equivalents, including:
• en36c – close equivalent
• din 1.5752 (high ni range, approximate)
• 18CrNimo7-6 – application-based comparison

Why choose En353 for your application?

En353 offers an exceptional combination of surface hardness, core toughness, and fatigue resistance. Its higher nickel content compared to En351 and En352 makes it ideal for heavily loaded components operating under severe service conditions.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
En353	0.10 – 0.20	Heavy gears, transmission parts	Carburizing + q&t	Very high ni, maximum toughness
En352	0.10 – 0.20	Gears, heavy automotive parts	Carburizing + q&t	High ni
En351	0.10 – 0.20	Automotive gears	Carburizing + q&t	Moderate ni
En36	0.12 – 0.18	Heavy-duty gears	Carburizing	Widely used ni-cr steel

Summary

En353 is a high nickel–chromium low carbon alloy steel optimized for heavy-duty case hardening applications. It provides a very hard, wear-resistant surface, an exceptionally tough core, and reliable long-term performance for critical automotive and engineering components.