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Steel Hardox 600 vs NM450

Steel · grade comparison

Steel Hardox 600 and NM450 are both steel grades. Hardox 600 is the stronger of the two: yield strength 1,650 MPa (239 ksi) against 1,250 MPa (181 ksi) for NM450, about 32% more; tensile strength follows at 2,000 MPa (290 ksi) vs 1,450 MPa (210 ksi). In exchange, NM450 is the more ductile: elongation 10% versus 7% for Hardox 600, and Hardox 600 is harder (600 HB vs 450 HB). NM450 conducts heat better (38 W/m·K vs 30 W/m·K). On the shop floor, NM450 welds better (good vs poor) and NM450 sits in a lower cost tier (budget, $) than Hardox 600 (standard, $$).

Hardox 600Choose it when strength drives the design.

NM450Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

Hardox 600 vs NM450: properties

Hardox 600NM450

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

2,000 MPa290 ksi
1,450 MPa210 ksi

Yield Strength (0.2% offset)

1,650 MPa239 ksi
1,250 MPa181 ksi

Elongation at Break

7%
10%

Reduction in Area

30%
40%

Compressive Strength

1,700 MPa247 ksi
1,250 MPa181 ksi

Shear Strength

1,200 MPa174 ksi
880 MPa128 ksi

Fatigue Strength (Endurance Limit)

750 MPa109 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

600 HB
450 HB

Hardness, Rockwell C

57 HRC
47 HRC

Hardness, Vickers

635 HV
470 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,420°C2,588 °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

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 · Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.7×10⁻⁷ Ω·m10.6 µΩ·in
2.5×10⁻⁷ Ω·m9.84 µΩ·in

Electrical Conductivity

—
7 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

8 / 100
15 / 100

Machinability Rating (AISI 1212 = 100 %)

7%
15%

Weldability

30 / 100
60 / 100

Formability (cold)

12 / 100
30 / 100

Polishability

55 / 100
45 / 100

Brazeability / Solderability

—
30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

50 L/kg6 gal/lb
45 L/kg5.4 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
185 kN·m/kg

Modulus of Resilience

6,482 kJ/m³
3,720 kJ/m³

Thermal Diffusivity

8.1 mm²/s
10.3 mm²/s

Thermal Shock Resistance Index

24
22

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 600NM450

Manufacturing and finishing

CapabilityHardox 600NM450
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 NM450 — frequently asked

Is Hardox 600 stronger than NM450?

Yes. Hardox 600 has a typical yield strength of 1,650 MPa (239 ksi) against 1,250 MPa (181 ksi) for NM450 — about 32% more. Tensile strength is 2,000 MPa (290 ksi) vs 1,450 MPa (210 ksi).

Which is cheaper, Hardox 600 or NM450?

NM450 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 NM450?

NM450. Its machinability rates poor (15/100) against not recommended (8/100) for Hardox 600; for welding the order is NM450 first (good, 60/100) then Hardox 600 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Hardox 600 and NM450 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.