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Steel G20CrNiMo vs SUJ2

Steel · grade comparison

Steel G20CrNiMo and SUJ2 are both steel grades. SUJ2 is the stronger of the two: tensile strength 660 MPa (95.7 ksi) against 620 MPa (89.9 ksi) for G20CrNiMo, about 6% more. In exchange, G20CrNiMo is the more ductile: elongation 29% versus 25% for SUJ2. G20CrNiMo runs hotter in service (400°C vs 200°C continuous) and G20CrNiMo conducts electricity better (8 % IACS vs 7 % IACS). On the shop floor, G20CrNiMo machines more easily (good vs fair), G20CrNiMo welds better (fair vs not recommended), and G20CrNiMo sits in a lower cost tier (budget, $) than SUJ2 (standard, $$).

G20CrNiMoChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SUJ2Choose it when strength drives the design.

G20CrNiMo vs SUJ2: properties

G20CrNiMoSUJ2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
420 MPa60.9 ksi

Elongation at Break

29%
25%

Reduction in Area

58%
45%

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
—

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

190 HB
192 HB

Hardness, Rockwell B

91 HRB
92 HRB

Compressive Strength

—
450 MPa65.3 ksi

Hardness, Vickers

—
200 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,500°C2,732 °F
1,460°C2,660 °F

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
11.9 µm/m·K6.6 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 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

60 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
40%

Weldability

50 / 100
12 / 100

Formability (cold)

55 / 100
35 / 100

Brazeability / Solderability

60 / 100
35 / 100

Polishability

80 / 100
85 / 100

Same in both: Castability 30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Water

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

Typical Recycled Content

25%
30%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
85 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.9 MN·m/kg

Modulus of Resilience

381 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.9 mm²/s
12.8 mm²/s

Thermal Shock Resistance Index

11
12

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 scaleSUJ2G20CrNiMo

Manufacturing and finishing

CapabilityG20CrNiMoSUJ2
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.

G20CrNiMo vs SUJ2 — frequently asked

Is SUJ2 stronger than G20CrNiMo?

Yes. SUJ2 has a typical tensile strength of 660 MPa (95.7 ksi) against 620 MPa (89.9 ksi) for G20CrNiMo — about 6% more.

Which is cheaper, G20CrNiMo or SUJ2?

G20CrNiMo is the lower-cost material: it sits in the budget tier ($) while SUJ2 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, G20CrNiMo or SUJ2?

G20CrNiMo. Its machinability rates good (60/100) against fair (45/100) for SUJ2; for welding the order is G20CrNiMo first (fair, 50/100) then SUJ2 (not recommended, 12/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in G20CrNiMo and SUJ2 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.