Quenched and Tempered Steel (4140 – 4340)

4140 – 4340 heat treatment steels are special steels preferred in applications requiring low alloy but high strength. These steels we offer with Mersin Steel - Çelik Boru quality provide superior mechanical properties thanks to chromium and molybdenum alloy elements.

• Chemical Composition
  • 0.38%–0.45% carbon content
  • 0.50%–0.80% manganese
  • 0.90%–1.20% chromium
  • 0.15%–0.30% molybdenum
  • 42CrMo4 (AISI/SAE 4140) quality
• Mechanical Properties
  • High tensile strength (900–1000 MPa)
  • Good ductility and toughness
  • Wear resistance
  • High impact strength
  • Long fatigue life
• Heat Treatment Properties
  • 820–860 °C hardening
  • 315–650 °C tempering
  • Fine tempered martensite structure
  • Surface hardening suitability
  • Induction and flame hardening

Application Areas

• Crankshafts
• Gears and axles
• Shafts and bolts
• Machine elements under high load
• Turbine shafts
• Automotive parts
• Defense industry applications
• Aviation industry
• Heavy machinery manufacturing

Quality Types and Differences

• 4140 (42CrMo4)
  • Most commonly used heat treatment steel
  • High tensile strength
  • Good ductility properties
  • Economic solution
• 4340 Steel
  • High impact strength with nickel content
  • Resistant to heavy shock loads
  • Aircraft landing gears
  • Military parts
• 42CrMoS4
  • Sulfur-containing variant
  • Machinability advantage
  • Easy chip removal
  • Production efficiency