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Steel Hardox 600 vs SHY685

Steel · grade comparison

Steel Hardox 600 and SHY685 are both steel grades. Hardox 600 is the stronger of the two: yield strength 1,650 MPa (239 ksi) against 730 MPa (106 ksi) for SHY685, about 126% more; tensile strength follows at 2,000 MPa (290 ksi) vs 830 MPa (120 ksi). In exchange, SHY685 is the more ductile: elongation 20% versus 7% for Hardox 600, and Hardox 600 is harder (600 HB vs 265 HB). SHY685 runs hotter in service (350°C vs 250°C continuous) and SHY685 conducts heat better (36 W/m·K vs 30 W/m·K). On the shop floor, SHY685 machines more easily (fair vs not recommended), SHY685 welds better (good vs poor), and SHY685 sits in a lower cost tier (budget, $) than Hardox 600 (standard, $$).

Hardox 600Choose it when strength drives the design.

SHY685Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

Hardox 600 vs SHY685: properties

Hardox 600SHY685

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

0.3
0.29

Tensile Strength (Ultimate)

2,000 MPa290 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

1,650 MPa239 ksi
730 MPa106 ksi

Elongation at Break

7%
20%

Reduction in Area

30%
55%

Compressive Strength

1,700 MPa247 ksi
730 MPa106 ksi

Shear Strength

1,200 MPa174 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

750 MPa109 ksi
390 MPa56.6 ksi

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

600 HB
265 HB

Hardness, Rockwell C

57 HRC
26 HRC

Hardness, Vickers

635 HV
278 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °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
36 W/m·K20.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

250°C482 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °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

Electrical

Conductivity and insulation.

Electrical Resistivity

2.7×10⁻⁷ Ω·m10.6 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Electrical Conductivity

—
7.2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Corrosion Resistance

15 / 100
13 / 100

Manufacturability

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

Machinability

8 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

7%
48%

Weldability

30 / 100
62 / 100

Formability (cold)

12 / 100
42 / 100

Polishability

55 / 100
50 / 100

Brazeability / Solderability

—
35 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

50 L/kg6 gal/lb
60 L/kg7.2 gal/lb

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

255 kN·m/kg
106 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

6,482 kJ/m³
1,293 kJ/m³

Thermal Diffusivity

8.1 mm²/s
9.8 mm²/s

Thermal Shock Resistance Index

24
12

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 600SHY685

Manufacturing and finishing

CapabilityHardox 600SHY685
Default condition——
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

Hardox 600 vs SHY685 — frequently asked

Is Hardox 600 stronger than SHY685?

Yes. Hardox 600 has a typical yield strength of 1,650 MPa (239 ksi) against 730 MPa (106 ksi) for SHY685 — about 126% more. Tensile strength is 2,000 MPa (290 ksi) vs 830 MPa (120 ksi).

Which is cheaper, Hardox 600 or SHY685?

SHY685 is the lower-cost material: it sits in the budget tier ($) while Hardox 600 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 600 or SHY685?

SHY685. Its machinability rates fair (38/100) against not recommended (8/100) for Hardox 600; for welding the order is SHY685 first (good, 62/100) then Hardox 600 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Hardox 600 and SHY685 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.