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Stainless Steel - Grade 440C / 1.4125

Description

440C / 1.4125 stainless steel is a high-carbon martensitic stainless steel known for its excellent hardness, wear resistance, and strength. It is primarily used in applications requiring high strength and corrosion resistance, such as bearing assemblies, cutlery, and valve components.

Chemical Composition

The typical chemical composition of 440C stainless steel is as follows:

  • Chromium (Cr): ≤ 1.00%
  • Manganese (Mn): 0.95 - 1.20%
  • Silicon (Si): ≤ 1.00%
  • Carbon (C): 0.95 - 1.20%
  • Phosphorus (P): ≤ 0.04%
  • Sulfur (S): ≤ 0.03%
  • Molybdenum (Mo): ≤ 0.75%
  • Iron (Fe): Balance.

    • Mechanical Properties

    Heat Treatment Temperature (°C) Tensile Strength (MPa) Yield Strength (MPa) Elongation (%) Hardness (HRC)
    Annealed 758 448 14 269 HB max
    204 2030 1900 4 59
    260 1960 1830 4 57
    316 1860 1740 4 56
    371 1790 1660 4 56

    Thermal & Physical Properties

  • Density: 7.62 g/cm³
  • Melting Point: Approx. 1400 - 1450°C (2552 - 2642°F)
  • Thermal Conductivity (212°F): 168.0 BTU-in/hr/ft²/°F
  • Specific Heat (32 to 212°F): 0.1100 Btu/lb/°F
  • Mean Coefficient of Thermal Expansion: 5.60×10−6
    5.60×10
    −6 in/in/°F
  • Modulus of Elasticity: 29.0 x 10³ ksi.

    • Other Designations

  • UNS: S44004
  • DIN: 1.4125
  • AISI: 440C
  • JIS: SUS440C
  • BS: X105CrMo17

    • Fabrication and Heat Treatment

  • Annealing: Heat to 843-871°C (1550-1600°F) and cool slowly.
  • Hardening: Heat to 1010-1065°C (1850-1950°F) and quench in oil or air.
  • Tempering: Temper at 149-177°C (300-350°F) for optimal hardness.

    • Applications

    440C stainless steel is widely used in:

  • Bearing assemblies (balls and races)
  • Cutlery
  • Valve components (needle valves, ball check valves)
  • Pump parts
  • Wear-resistant components in textile machinery.

    • Supplied Forms

    440C / 1.4125 stainless steel is available in various forms, including:

  • Round bars (diameter 1mm to 400mm)
  • Plates (thickness 0.1-100mm, width 500-2000mm, length 1000-6000mm)
  • Sheets, coils, and custom shapes upon request.

    • Features

  • High hardness and wear resistance after heat treatment
  • Good corrosion resistance in mild environments
  • Capability of achieving Rockwell hardness up to C60 when properly treated.

    • This datasheet provides a comprehensive overview of 440C / 1.4125stainless steel, highlighting its properties, applications, and treatment processes.

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