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Steel Hardox 500 vs Q690Q

Steel · grade comparison

Steel Hardox 500 and Q690Q are both steel grades. Hardox 500 is the stronger of the two: yield strength 1,300 MPa (189 ksi) against 750 MPa (109 ksi) for Q690Q, about 73% more; tensile strength follows at 1,600 MPa (232 ksi) vs 830 MPa (120 ksi). In exchange, Q690Q is the more ductile: elongation 16% versus 8% for Hardox 500, and Hardox 500 is harder (500 HB vs 260 HB). Q690Q runs hotter in service (350°C vs 250°C continuous) and Q690Q conducts heat better (38 W/m·K vs 30 W/m·K). On the shop floor, Q690Q machines more easily (fair vs poor) and Q690Q sits in a lower cost tier (budget, $) than Hardox 500 (standard, $$).

Hardox 500Choose it when strength drives the design.

Q690QChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

Hardox 500 vs Q690Q: properties

Hardox 500Q690Q

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Tensile Strength (Ultimate)

1,600 MPa232 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

1,300 MPa189 ksi
750 MPa109 ksi

Elongation at Break

8%
16%

Compressive Strength

1,300 MPa189 ksi
750 MPa109 ksi

Shear Strength

960 MPa139 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

650 MPa94.3 ksi
380 MPa55.1 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

500 HB
260 HB

Hardness, Rockwell C

50 HRC
26 HRC

Hardness, Vickers

530 HV
273 HV

Reduction in Area

—
55%

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

30 W/m·K17.3 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Max Service Temperature (continuous)

250°C482 °F
350°C662 °F

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 · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6 % IACS
7.2 % IACS

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
14 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V

Manufacturability

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

Machinability

22 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

18%
45%

Weldability

55 / 100
62 / 100

Formability (cold)

25 / 100
45 / 100

Polishability

60 / 100
55 / 100

Brazeability / Solderability

—
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

25%
22%

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

204 kN·m/kg
106 kN·m/kg

Modulus of Resilience

4,024 kJ/m³
1,339 kJ/m³

Thermal Diffusivity

8.1 mm²/s
10.3 mm²/s

Thermal Shock Resistance Index

19
13

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg

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 scaleHardox 500Q690Q

Manufacturing and finishing

CapabilityHardox 500Q690Q
CNC machiningYes—
Sheet metalYes—
Default conditionQ&T—
Relative cost$$ Standard$ 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.

Hardox 500 vs Q690Q — frequently asked

Is Hardox 500 stronger than Q690Q?

Yes. Hardox 500 has a typical yield strength of 1,300 MPa (189 ksi) against 750 MPa (109 ksi) for Q690Q — about 73% more. Tensile strength is 1,600 MPa (232 ksi) vs 830 MPa (120 ksi).

Which is cheaper, Hardox 500 or Q690Q?

Q690Q is the lower-cost material: it sits in the budget tier ($) while Hardox 500 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, Hardox 500 or Q690Q?

Q690Q. Its machinability rates fair (42/100) against poor (22/100) for Hardox 500; for welding the order is Q690Q first (good, 62/100) then Hardox 500 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Hardox 500 and Q690Q 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.