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Steel Q215 vs Q235B

Steel · grade comparison

Steel Q215 and Q235B are both steel grades. Q235B is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 235 MPa (34.1 ksi) for Q215, about 6% more; tensile strength follows at 420 MPa (60.9 ksi) vs 390 MPa (56.6 ksi). In exchange, Q215 is the more ductile: elongation 33% versus 28% for Q235B.

Q215Choose it when the part is bent, formed or impact-loaded.

Q235BChoose it when strength drives the design.

Q215 vs Q235B: properties

Q215Q235B

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

Poisson's Ratio

0.28
0.3

Tensile Strength (Ultimate)

390 MPa56.6 ksi
420 MPa60.9 ksi

Yield Strength (0.2% offset)

235 MPa34.1 ksi
250 MPa36.3 ksi

Elongation at Break

33%
28%

Reduction in Area

58%
55%

Compressive Strength

235 MPa34.1 ksi
250 MPa36.3 ksi

Fatigue Strength (Endurance Limit)

175 MPa25.4 ksi
190 MPa27.6 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

116 HB
120 HB

Hardness, Rockwell B

65 HRB
67 HRB

Hardness, Vickers

122 HV
126 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Shear Strength 260 MPa37.7 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,525°C2,777 °F
1,520°C2,768 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

51 W/m·K29.5 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Latent Heat of Fusion

247 J/g106 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

11 % IACS
10.8 % IACS

Same in both: Electrical Resistivity 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

Same in both: Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

62 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
70%

Formability (cold)

90 / 100
85 / 100

Brazeability / Solderability

70 / 100
65 / 100

Castability

—
40 / 100

Same in both: Weldability 95 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

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

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

50 kN·m/kg
54 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

131 kJ/m³
152 kJ/m³

Thermal Diffusivity

13.8 mm²/s
13.6 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleQ235BQ215

Manufacturing and finishing

CapabilityQ215Q235B
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.

Q215 vs Q235B — frequently asked

Is Q235B stronger than Q215?

Yes. Q235B has a typical yield strength of 250 MPa (36.3 ksi) against 235 MPa (34.1 ksi) for Q215 — about 6% more. Tensile strength is 420 MPa (60.9 ksi) vs 390 MPa (56.6 ksi).

Which is cheaper, Q215 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.

When should I choose Q215 over Q235B?

Pick Q215 when the part is bent, formed or impact-loaded. Pick Q235B when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q215 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.