Heat Treatment & Induction Hardening for EN Series Steels — EN8, EN19, EN24
From automotive shafts to industrial gears and axles, the EN series steels are among the most widely used materials in Punjab’s manufacturing ecosystem.
At Thakur Induction, Ludhiana, we specialize in heat treatment for EN steels, optimizing hardness, fatigue resistance, and wear strength through advanced induction processes tailored to each grade.
What Are EN Series Steels?
The “EN” in EN steels stands for European Norms, a classification for engineering steels. Each EN grade has specific mechanical properties and alloy compositions, making it suitable for different applications and heat treatment techniques.
| Steel Grade | Equivalent (AISI) | Carbon % | Key Alloying Elements | Typical Application |
|---|---|---|---|---|
| EN8 | C40 / 1040 | 0.40 | None (Plain Carbon) | Shafts, Pins, Gears |
| EN19 | 4140 | 0.40 | Cr, Mo | Gears, Crankshafts, Shafts |
| EN24 | 4340 | 0.40 | Ni, Cr, Mo | Axles, Spindles, Heavy Gears |
EN8 Heat Treatment – Medium Carbon Steel
EN8 is a medium carbon steel known for its excellent balance of strength, hardness, and toughness. It is one of the most commonly used steels in Ludhiana’s automotive and machine part manufacturing industries.
EN8 Heat Treatment Process:
- Induction Heating: Heated to ~850°C using medium frequency for surface hardening.
- Quenching: Rapidly cooled using polymer or water, creating a hard martensitic layer.
- Tempering (Optional): Reheated to ~150–200°C to relieve stress and enhance ductility.
EN19 Induction Hardening – Chromium-Molybdenum Alloy Steel
EN19, equivalent to AISI 4140, is an alloy steel with chromium and molybdenum additions that provide deep hardenability and high fatigue strength. It is widely used in components that experience torsional and bending loads.
EN19 Induction Hardening Process:
- Induction Heating: Heated to 850–900°C using medium frequency.
- Quenching: Polymer quenching used for controlled cooling and reduced distortion.
- Tempering: Carried out at ~200°C to enhance impact toughness.
EN24 Steel Hardening – Nickel-Chromium-Molybdenum Alloy Steel
EN24 (AISI 4340) is a high-strength alloy steel known for exceptional toughness and deep hardenability. It is used in critical, high-stress parts that must endure impact, bending, and rotational forces.
EN24 Heat Treatment Process:
- Induction Heating: Surface heated to 870–900°C using high frequency.
- Polymer Quenching: Ensures deep hardening with minimal distortion.
- Tempering: Carried out at ~250°C for stability and shock resistance.
Role of Quenching in EN Steel Hardening
The quenching stage plays a crucial role in determining surface hardness and structure. At Thakur Induction, both water and polymer quenching systems are used depending on component geometry and alloy composition.
| Quenching Type | Suitable For | Cooling Rate | Key Benefit |
|---|---|---|---|
| Water Quenching | EN8, large parts | Fast | Deep case hardness |
| Polymer Quenching | EN19, EN24, precision parts | Controlled | Reduced distortion & cracking |
Conclusion: Reliable Heat Treatment for EN Steels in Punjab
The heat treatment for EN steels is the foundation of high-quality manufacturing in Punjab’s industrial ecosystem. Through precise induction hardening, controlled quenching, and tempering, Thakur Induction ensures that each component achieves optimal hardness, fatigue strength, and dimensional stability.
Need Induction Hardening for EN Steels?
Get in touch with Thakur Induction for professional heat treatment and induction hardening job work for EN8, EN19, and EN24 materials.