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Steel 52100 vs 9Cr18Mo

Steel · grade comparison

Steel 52100 and 9Cr18Mo are both steel grades. 9Cr18Mo is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 415 MPa (60.2 ksi) for 52100, about 4.6 times as much; tensile strength follows at 1,970 MPa (286 ksi) vs 690 MPa (100 ksi). In exchange, 52100 is the more ductile: elongation 25% versus 2% for 9Cr18Mo, and 9Cr18Mo is harder (680 HV vs 205 HV). 52100 conducts heat better (46 W/m·K vs 24.2 W/m·K). On the shop floor, 52100 machines more easily (fair vs not recommended).

52100Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

9Cr18MoChoose it when strength drives the design.

52100 vs 9Cr18Mo: properties

521009Cr18Mo

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
200 GPa29 Msi

Shear Modulus

80 GPa11.6 Msi
78 GPa11.3 Msi

Bulk Modulus

166 GPa24.1 Msi
160 GPa23.2 Msi

Poisson's Ratio

0.3
0.28

Tensile Strength (Ultimate)

690 MPa100 ksi
1,970 MPa286 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
1,900 MPa276 ksi

Elongation at Break

25%
2%

Reduction in Area

45%
4%

Compressive Strength

430 MPa62.4 ksi
2,250 MPa326 ksi

Shear Strength

420 MPa60.9 ksi
1,180 MPa171 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
780 MPa113 ksi

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
9 J6.6 ft·lbf

Hardness, Brinell

195 HB
—

Hardness, Rockwell B

93 HRB
—

Hardness, Vickers

205 HV
680 HV

Fracture Toughness (K_IC)

—
22 MPa·√m20 ksi·√in

Hardness, Rockwell C

—
59 HRC

Physical

Density and transition temperatures.

Density

7.81 g/cm³0.28 lb/in³
7.7 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,424°C2,595 °F
1,370°C2,498 °F

Liquidus Temperature

1,455°C2,651 °F
1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
24.2 W/m·K14 BTU/hr·ft·°F

Specific Heat Capacity

475 J/kg·K0.11 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.9 µm/m·K6.6 µin/in·°F
10.2 µm/m·K5.7 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
2.9 % IACS

Electrical Resistivity

2.5×10⁻⁷ Ω·m9.84 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.3 V

Corrosion Resistance

12 / 100
55 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

40 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
8%

Formability (cold)

35 / 100
5 / 100

Castability

25 / 100
35 / 100

Brazeability / Solderability

35 / 100
40 / 100

Polishability

85 / 100
78 / 100

Same in both: Weldability 12 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
4.5 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
90 L/kg10.8 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

88 kN·m/kg
256 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26 MN·m/kg

Modulus of Resilience

420 kJ/m³
9,025 kJ/m³

Thermal Diffusivity

12.4 mm²/s
6.8 mm²/s

Thermal Shock Resistance Index

13
23

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale521009Cr18Mo

Manufacturing and finishing

Capability521009Cr18Mo
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

52100 vs 9Cr18Mo — frequently asked

Is 9Cr18Mo stronger than 52100?

Yes. 9Cr18Mo has a typical yield strength of 1,900 MPa (276 ksi) against 415 MPa (60.2 ksi) for 52100 — about 4.6 times as much. Tensile strength is 1,970 MPa (286 ksi) vs 690 MPa (100 ksi).

Which is cheaper, 52100 or 9Cr18Mo?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 52100 or 9Cr18Mo?

52100. Its machinability rates fair (40/100) against not recommended (10/100) for 9Cr18Mo.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 52100 and 9Cr18Mo side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.