9Cr18Mo Stainless Steel Equivalent, Chemical Composition, Mechanical Properties

9Cr18Mo Stainless Steel

9Cr18Mo steel is a Chinese GB standard martensitic stainless steel, after quenching, it has high hardness and wear resistance high temperature and low temperature dimensional stability. 9Cr18Mo stainless steel has similar properties and uses as 9Cr18, but has higher heat resistance and tempering resistance after quenching, Molybdenum (Mo) can increase the passivation effect of stainless steel.

Note: 9Cr18Mo (old name) = 102Cr17Mo (new name)

Datasheet and Specification

The tables below list 9Cr18Mo datasheet such as chemical composition and mechanical properties, etc.

9Cr18Mo Steel Chemical Composition

The following table shows the chemical compostion of 9Cr18Mo steel (102Cr17Mo).

Chemical Composition (%)
Standard Steel Grade C Si (≤) Mn (≤) P (≤) S (≤) Ni (≤) Cr Mo
GB/T 1220 9Cr18Mo
0.95-1.10 0.80 0.80 0.040 0.030 (0.60) 16.00-18.00 0.40-0.70

Notes: The value in parentheses is the maximum value that can be added or allowed.

Mechanical Properties of 102Cr17Mo Steel

  • Material Rockwell hardness: ≥55 HRC (Quenching and tempering)
  • Material Brinell hardness: ≤269 HBW (steel bar after annealing)

Physical Properties

  • Density (g/cm3): 7.70
  • Specific heat capacity (J/Kg·K): 430 at 0-100℃
  • Thermal conductivity (W/m·K): 16.0 at 100℃
  • Coefficients of linear thermal expansion (10-6/K):
    • 10.4 (0-100℃)
    • 11.6 (0-500℃)
  • Electrical Resistivity (μΩ·m): 0.80 at 20℃
  • Longitudinal modulus of elasticity (kN/mm2): 215 at 20℃
  • Magnetic: Yes

Typical Heat Treatment

  • Annealing temperature of steel bars: 800-900℃ (Slow cooling)
  • Sample quenching temperature: 1000-1050℃ (Oil cooling)
  • Sample tempering temperature: 200-300℃ (Air cooling)


9Cr18Mo steel is mainly used to manufacture parts in friction and corrosive media, such as mechanical cutting tools, shearing tools, knives, surgical blades, bearing rings and balls, valve parts, nozzles, measuring tools and other high wear-resistant parts.

Equivalent Grade

9Cr18Mo steel equivalent to US ASTM, ISO, European EN (Germany DIN, United Kingdom BSI) and Japanese JIS standard for reference.

9Cr18Mo steel equivalent grade
China US European Germany ISO Japan
Standard Grade Standard Grade Standard Grade (Steel number) Standard Grade Standard Grade Standard Grade
GB/T 1220 9Cr18Mo
ASTM A276/A276M
440C EN 10088-3 X105CrMo17 (1.4125) DIN EN 10088-3 X105CrMo17
ISO 683-17 X108CrMo17 JIS G 4303 SUS 440C

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