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Steel Q235B vs S275N

Steel · grade comparison

Steel Q235B and S275N are both steel grades. S275N is the stronger of the two: yield strength 300 MPa (43.5 ksi) against 250 MPa (36.3 ksi) for Q235B, about 20% more; tensile strength follows at 450 MPa (65.3 ksi) vs 420 MPa (60.9 ksi). S275N is harder — 135 HB against 120 HB for Q235B — which matters for wear surfaces and threads. S275N runs hotter in service (400°C vs 350°C continuous). On the shop floor, Q235B forms better (excellent vs very good).

S275NChoose it when strength drives the design, or when surface hardness matters.

Q235B vs S275N: properties

Q235BS275N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
210 GPa30.5 Msi

Shear Modulus

79 GPa11.5 Msi
81 GPa11.7 Msi

Tensile Strength (Ultimate)

420 MPa60.9 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
300 MPa43.5 ksi

Elongation at Break

28%
27%

Compressive Strength

250 MPa36.3 ksi
300 MPa43.5 ksi

Shear Strength

260 MPa37.7 ksi
285 MPa41.3 ksi

Fatigue Strength (Endurance Limit)

190 MPa27.6 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

120 HB
135 HB

Hardness, Rockwell B

67 HRB
75 HRB

Hardness, Vickers

126 HV
142 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Reduction in Area 55%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,495°C2,723 °F
1,425°C2,597 °F

Liquidus Temperature

1,520°C2,768 °F
1,510°C2,750 °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

50 W/m·K28.9 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Specific Heat Capacity

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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
10.5 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
1.65×10⁻⁷ Ω·m6.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.63 V
-0.62 V

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability

65 / 100
62 / 100

Weldability

95 / 100
92 / 100

Formability (cold)

85 / 100
70 / 100

Castability

40 / 100
—

Brazeability / Solderability

65 / 100
60 / 100

Polishability

40 / 100
45 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 70%

Sustainability

Primary-production footprint per kilogram.

Embodied Water

30 L/kg3.6 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

25%
30%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
57 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

152 kJ/m³
214 kJ/m³

Thermal Diffusivity

13.6 mm²/s
13.3 mm²/s

Thermal Shock Resistance Index

8
9

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 scaleQ235BS275N

Manufacturing and finishing

CapabilityQ235BS275N
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

Q235B vs S275N — frequently asked

Is S275N stronger than Q235B?

Yes. S275N has a typical yield strength of 300 MPa (43.5 ksi) against 250 MPa (36.3 ksi) for Q235B — about 20% more. Tensile strength is 450 MPa (65.3 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, Q235B or S275N?

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 Q235B over S275N?

Pick S275N when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q235B and S275N 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.