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Steel Q275 vs SPHC

Steel · grade comparison

Steel Q275 and SPHC are both steel grades, both structural steel. Q275 is the stronger of the two: yield strength 295 MPa (42.8 ksi) against 240 MPa (34.8 ksi) for SPHC, about 23% more; tensile strength follows at 470 MPa (68.2 ksi) vs 310 MPa (45 ksi). In exchange, SPHC is the more ductile: elongation 38% versus 24% for Q275, and Q275 is harder (143 HB vs 110 HB). SPHC runs hotter in service (400°C vs 350°C continuous). On the shop floor, SPHC welds better (excellent vs good).

Q275Choose it when strength drives the design.

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

Q275 vs SPHC: properties

Q275SPHC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

470 MPa68.2 ksi
310 MPa45 ksi

Yield Strength (0.2% offset)

295 MPa42.8 ksi
240 MPa34.8 ksi

Elongation at Break

24%
38%

Reduction in Area

45%
60%

Compressive Strength

295 MPa42.8 ksi
—

Shear Strength

300 MPa43.5 ksi
210 MPa30.5 ksi

Fatigue Strength (Endurance Limit)

210 MPa30.5 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

143 HB
110 HB

Hardness, Rockwell B

77 HRB
64 HRB

Hardness, Vickers

150 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.

Melting Point (Solidus)

1,425°C2,597 °F
1,495°C2,723 °F

Liquidus Temperature

1,500°C2,732 °F
1,530°C2,786 °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

48 W/m·K27.7 BTU/hr·ft·°F
52 W/m·K30 BTU/hr·ft·°F

Specific Heat Capacity

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

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 · Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
10.5 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 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)

-0.61 V
-0.62 V

Corrosion Resistance

11 / 100
10 / 100

Manufacturability

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

Machinability

60 / 100
68 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
68%

Weldability

68 / 100
95 / 100

Formability (cold)

55 / 100
80 / 100

Brazeability / Solderability

60 / 100
70 / 100

Polishability

45 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

60 kN·m/kg
39 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

211 kJ/m³
140 kJ/m³

Thermal Diffusivity

13 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 scaleSPHCQ275

Manufacturing and finishing

CapabilityQ275SPHC
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.

Q275 vs SPHC — frequently asked

Is Q275 stronger than SPHC?

Yes. Q275 has a typical yield strength of 295 MPa (42.8 ksi) against 240 MPa (34.8 ksi) for SPHC — about 23% more. Tensile strength is 470 MPa (68.2 ksi) vs 310 MPa (45 ksi).

Which is cheaper, Q275 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.

Which is easier to machine, Q275 or SPHC?

SPHC, by a small margin. Both rate good for machinability — 68/100 against 60/100 for Q275; for welding the order is SPHC first (excellent, 95/100) then Q275 (good, 68/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q275 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.