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DIN 1.7225

High-strength hardened alloy steel

DIN 1.7225 is an alloyed structural steel known as 42CrMo4, often used for components with high mechanical loads. It stands out for its high strength, toughness, durability and very good hardenability. It is ideal for the production of demanding parts such as shafts, pins, gears and pressure components. We supply in a hardened state + QT.


Alternative designation: 42CrMo4 + QT, ČSN 15142
Type: Alloy quenched and tempered steel

Heat treatment:

  • Soft annealing: 650–700 °C

  • Refinement (hardening + tempering):

  • Quenching: 830–870 °C (oil)

  • Tempering: 540–680 °C depending on the required strength/hardness

  • Induction hardening: possible for surface hardening (e.g. gearing)

Round bars, rolled, tempered to 900-1000 N/mm2

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Forged blocks, tempered to 900-1000 N/mm2


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Rolled sheets, tempered to 900-1000 N/mm2

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Features:

  • High strength and fatigue limit after tempering

  • Good toughness even with larger cross-sections

  • Very good machinability in the annealed condition

  • Easily hardenable – also suitable for induction hardening

  • Limited weldability – preheating and post-welding tempering required

  • Hardness after hardening up to approx. 50–55 HRC

Use:

  • Highly stressed shafts, pins, gears

  • Connecting parts, screws, rods

  • Pressure vessels, hydraulic and pneumatic components

  • Parts requiring high strength and impact resistance

  • Tools, fixtures and machine components with loads during operation

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