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Steel E420 vs Q235B

Steel · grade comparison

Steel E420 and Q235B are both steel grades. E420 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 250 MPa (36.3 ksi) for Q235B, about 80% more; tensile strength follows at 620 MPa (89.9 ksi) vs 420 MPa (60.9 ksi). In exchange, Q235B is the more ductile: elongation 28% versus 19% for E420, and E420 is harder (185 HB vs 120 HB). Q235B conducts heat better (50 W/m·K vs 45 W/m·K). On the shop floor, Q235B machines more easily (65 vs 55 out of 100) and Q235B welds better (excellent vs very good).

E420Choose it when strength drives the design.

Q235BChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

E420 vs Q235B: properties

E420Q235B

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

81 GPa11.7 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
420 MPa60.9 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
250 MPa36.3 ksi

Elongation at Break

19%
28%

Reduction in Area

45%
55%

Compressive Strength

450 MPa65.3 ksi
250 MPa36.3 ksi

Shear Strength

380 MPa55.1 ksi
260 MPa37.7 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
190 MPa27.6 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

185 HB
120 HB

Hardness, Rockwell B

91 HRB
67 HRB

Hardness, Vickers

195 HV
126 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,495°C2,723 °F

Liquidus Temperature

1,510°C2,750 °F
1,520°C2,768 °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

45 W/m·K26 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
10.8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
1.6×10⁻⁷ Ω·m6.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.63 V

Corrosion Resistance

12 / 100
10 / 100

Manufacturability

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

Machinability

55 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
70%

Weldability

72 / 100
95 / 100

Formability (cold)

55 / 100
85 / 100

Brazeability / Solderability

55 / 100
65 / 100

Polishability

45 / 100
40 / 100

Castability

—
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
30 L/kg3.6 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
54 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

482 kJ/m³
152 kJ/m³

Thermal Diffusivity

12.2 mm²/s
13.6 mm²/s

Thermal Shock Resistance Index

11
8

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 scaleQ235BE420

Manufacturing and finishing

CapabilityE420Q235B
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$ Budget
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.

E420 vs Q235B — frequently asked

Is E420 stronger than Q235B?

Yes. E420 has a typical yield strength of 450 MPa (65.3 ksi) against 250 MPa (36.3 ksi) for Q235B — about 80% more. Tensile strength is 620 MPa (89.9 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, E420 or Q235B?

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

Which is easier to machine, E420 or Q235B?

Q235B, by a small margin. Both rate good for machinability — 65/100 against 55/100 for E420; for welding the order is Q235B first (excellent, 95/100) then E420 (very good, 72/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E420 and Q235B 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.