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Steel 20CrNiMo vs 4620

Steel · grade comparison

Steel 20CrNiMo and 4620 are both steel grades. 20CrNiMo is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 360 MPa (52.2 ksi) for 4620, about 8% more; tensile strength follows at 610 MPa (88.5 ksi) vs 570 MPa (82.7 ksi). 20CrNiMo is harder — 175 HB against 163 HB for 4620 — which matters for wear surfaces and threads. On the shop floor, 4620 welds better (65 vs 55 out of 100) and 20CrNiMo sits in a lower cost tier (budget, $) than 4620 (standard, $$).

20CrNiMoChoose it when strength drives the design, or when surface hardness matters.

4620Choose it when it will be welded.

20CrNiMo vs 4620: properties

20CrNiMo4620

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

610 MPa88.5 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

390 MPa56.6 ksi
360 MPa52.2 ksi

Elongation at Break

28%
26%

Reduction in Area

58%
55%

Compressive Strength

400 MPa58 ksi
—

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
—

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

175 HB
163 HB

Hardness, Rockwell B

88 HRB
84 HRB

Hardness, Vickers

185 HV
—

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 380 MPa55.1 ksi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

58 / 100
57 / 100

Weldability

55 / 100
65 / 100

Formability (cold)

55 / 100
58 / 100

Brazeability / Solderability

65 / 100
70 / 100

Polishability

60 / 100
55 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 65%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

33 MJ/kg14,187 BTU/lb
29 MJ/kg12,468 BTU/lb

Typical Recycled Content

25%
30%

Same in both: Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

78 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

362 kJ/m³
316 kJ/m³

Thermal Diffusivity

11.8 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 scale462020CrNiMo

Manufacturing and finishing

Capability20CrNiMo4620
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.

20CrNiMo vs 4620 — frequently asked

Is 20CrNiMo stronger than 4620?

Yes. 20CrNiMo has a typical yield strength of 390 MPa (56.6 ksi) against 360 MPa (52.2 ksi) for 4620 — about 8% more. Tensile strength is 610 MPa (88.5 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, 20CrNiMo or 4620?

20CrNiMo 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, 20CrNiMo or 4620?

4620. Its weldability rates good (65/100) against good (55/100) for 20CrNiMo.

Ready to make it?

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