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Steel 20CrMnMo vs 4620

Steel · grade comparison

Steel 20CrMnMo and 4620 are both steel grades. 20CrMnMo is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 360 MPa (52.2 ksi) for 4620, about 17% more; tensile strength follows at 650 MPa (94.3 ksi) vs 570 MPa (82.7 ksi). In exchange, 4620 is the more ductile: elongation 26% versus 20% for 20CrMnMo, and 20CrMnMo is harder (197 HB vs 163 HB). 20CrMnMo runs hotter in service (450°C vs 400°C continuous). On the shop floor, 4620 welds better (good vs fair) and 20CrMnMo sits in a lower cost tier (budget, $) than 4620 (standard, $$).

20CrMnMoChoose it when strength drives the design, or when the part sees heat.

4620Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

20CrMnMo vs 4620: properties

20CrMnMo4620

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

650 MPa94.3 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
360 MPa52.2 ksi

Elongation at Break

20%
26%

Compressive Strength

430 MPa62.4 ksi
—

Shear Strength

400 MPa58 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
260 MPa37.7 ksi

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

197 HB
163 HB

Hardness, Rockwell B

92 HRB
84 HRB

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55%

Physical

Density and transition temperatures.

Liquidus Temperature

1,495°C2,723 °F
1,500°C2,732 °F

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

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

450°C842 °F
400°C752 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8 % IACS

Same in both: 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)

-0.55 V
-0.61 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

58 / 100
57 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
65%

Weldability

35 / 100
65 / 100

Formability (cold)

45 / 100
58 / 100

Brazeability / Solderability

55 / 100
70 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
55 L/kg6.6 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

83 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

420 kJ/m³
316 kJ/m³

Thermal Diffusivity

11.4 mm²/s
12.3 mm²/s

Same in both: Thermal Shock Resistance Index 11

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 scale462020CrMnMo

Manufacturing and finishing

Capability20CrMnMo4620
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
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.

20CrMnMo vs 4620 — frequently asked

Is 20CrMnMo stronger than 4620?

Yes. 20CrMnMo has a typical yield strength of 420 MPa (60.9 ksi) against 360 MPa (52.2 ksi) for 4620 — about 17% more. Tensile strength is 650 MPa (94.3 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, 20CrMnMo or 4620?

20CrMnMo is the lower-cost material: it sits in the budget tier ($) while 4620 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 welds better, 20CrMnMo or 4620?

4620. Its weldability rates good (65/100) against fair (35/100) for 20CrMnMo.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20CrMnMo and 4620 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.