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Steel Q235A vs SPHC

Steel · grade comparison

Steel Q235A and SPHC are both steel grades, both structural steel. Q235A is the stronger of the two: yield strength 255 MPa (37 ksi) against 240 MPa (34.8 ksi) for SPHC, about 6% more; tensile strength follows at 420 MPa (60.9 ksi) vs 310 MPa (45 ksi). In exchange, SPHC is the more ductile: elongation 38% versus 28% for Q235A, and Q235A is harder (131 HB vs 110 HB). SPHC runs hotter in service (400°C vs 350°C continuous).

Q235AChoose it when strength drives the design.

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

Q235A vs SPHC: properties

Q235ASPHC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

420 MPa60.9 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

255 MPa37 ksi
240 MPa34.8 ksi

Elongation at Break

28%
38%

Reduction in Area

55%
60%

Compressive Strength

255 MPa37 ksi
—

Shear Strength

265 MPa38.4 ksi
210 MPa30.5 ksi

Fatigue Strength (Endurance Limit)

185 MPa26.8 ksi
155 MPa22.5 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

131 HB
110 HB

Hardness, Rockwell B

72 HRB
64 HRB

Hardness, Vickers

138 HV
115 HV

Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,520°C2,768 °F
1,530°C2,786 °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

50 W/m·K28.9 BTU/hr·ft·°F
52 W/m·K30 BTU/hr·ft·°F

Specific Heat Capacity

472 J/kg·K0.11 BTU/lb·°F
480 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.9 µm/m·K6.6 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
247 J/g106 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

0°C32 °F
-20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

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

Same in both: Electrical Conductivity 10.5 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.62 V

Same in both: Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

65 / 100
68 / 100

Weldability

92 / 100
95 / 100

Formability (cold)

82 / 100
80 / 100

Castability

35 / 100
—

Brazeability / Solderability

75 / 100
70 / 100

Polishability

45 / 100
40 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 68%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Water

35 L/kg4.2 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

20%
25%

Same in both: Embodied Carbon (primary production) 2.1 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

54 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

158 kJ/m³
140 kJ/m³

Thermal Diffusivity

13.5 mm²/s
13.8 mm²/s

Thermal Shock Resistance Index

9
7

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 scaleSPHCQ235A

Manufacturing and finishing

CapabilityQ235ASPHC
CNC machiningYes—
Default conditionHRHR
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

Q235A vs SPHC — frequently asked

Is Q235A stronger than SPHC?

Yes. Q235A has a typical yield strength of 255 MPa (37 ksi) against 240 MPa (34.8 ksi) for SPHC — about 6% more. Tensile strength is 420 MPa (60.9 ksi) vs 310 MPa (45 ksi).

Which is cheaper, Q235A or SPHC?

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 Q235A over SPHC?

Pick Q235A when strength drives the design. Pick SPHC when the part is bent, formed or impact-loaded, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q235A and SPHC 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.