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Steel 37CrMo4 vs 55Cr3

Steel · grade comparison

Steel 37CrMo4 and 55Cr3 are both steel grades. 37CrMo4 is the stronger of the two: yield strength 780 MPa (113 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 63% more; tensile strength follows at 1,000 MPa (145 ksi) vs 800 MPa (116 ksi). In exchange, 55Cr3 is the more ductile: elongation 16% versus 13% for 37CrMo4, and 37CrMo4 is harder (300 HB vs 225 HB). On the shop floor, 37CrMo4 sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

37CrMo4Choose it when strength drives the design, or when cost is the deciding factor.

55Cr3Choose it when the part is bent, formed or impact-loaded.

37CrMo4 vs 55Cr3: properties

37CrMo455Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

1,000 MPa145 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

780 MPa113 ksi
480 MPa69.6 ksi

Elongation at Break

13%
16%

Reduction in Area

50%
40%

Compressive Strength

790 MPa115 ksi
480 MPa69.6 ksi

Shear Strength

620 MPa89.9 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

480 MPa69.6 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

300 HB
225 HB

Hardness, Rockwell C

31 HRC
20 HRC

Hardness, Vickers

315 HV
236 HV

Hardness, Rockwell B

—
98 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
—

Corrosion Resistance

12 / 100
10 / 100

Manufacturability

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

Machinability

42 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
55%

Weldability

30 / 100
25 / 100

Formability (cold)

20 / 100
45 / 100

Brazeability / Solderability

55 / 100
40 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

27 MJ/kg11,608 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Embodied Carbon (primary production) 2 kg CO₂/kg · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

127 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

1,449 kJ/m³
559 kJ/m³

Thermal Diffusivity

11.6 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

16
14

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 scale55Cr337CrMo4

Manufacturing and finishing

Capability37CrMo455Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

37CrMo4 vs 55Cr3 — frequently asked

Is 37CrMo4 stronger than 55Cr3?

Yes. 37CrMo4 has a typical yield strength of 780 MPa (113 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 63% more. Tensile strength is 1,000 MPa (145 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 37CrMo4 or 55Cr3?

37CrMo4 is the lower-cost material: it sits in the budget tier ($) while 55Cr3 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 37CrMo4 or 55Cr3?

55Cr3, by a small margin. Both rate fair for machinability — 50/100 against 42/100 for 37CrMo4; for welding the order is 37CrMo4 first (poor, 30/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 37CrMo4 and 55Cr3 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.