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Steel Hardox 500 vs NM450

Steel · grade comparison

Steel Hardox 500 and NM450 are both steel grades. Hardox 500 is the stronger of the two: tensile strength 1,600 MPa (232 ksi) against 1,450 MPa (210 ksi) for NM450, about 10% more. In exchange, NM450 is the more ductile: elongation 10% versus 8% for Hardox 500, and Hardox 500 is harder (500 HB vs 450 HB). NM450 conducts heat better (38 W/m·K vs 30 W/m·K). On the shop floor, NM450 sits in a lower cost tier (budget, $) than Hardox 500 (standard, $$).

Hardox 500Choose it when strength drives the design.

NM450Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

Hardox 500 vs NM450: properties

Hardox 500NM450

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

1,600 MPa232 ksi
1,450 MPa210 ksi

Yield Strength (0.2% offset)

1,300 MPa189 ksi
1,250 MPa181 ksi

Elongation at Break

8%
10%

Compressive Strength

1,300 MPa189 ksi
1,250 MPa181 ksi

Shear Strength

960 MPa139 ksi
880 MPa128 ksi

Fatigue Strength (Endurance Limit)

650 MPa94.3 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

500 HB
450 HB

Hardness, Rockwell C

50 HRC
47 HRC

Hardness, Vickers

530 HV
470 HV

Reduction in Area

—
40%

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · 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 Conductivity

6 % IACS
7 % IACS

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 µΩ·in
2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.6 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

22 / 100
15 / 100

Machinability Rating (AISI 1212 = 100 %)

18%
15%

Weldability

55 / 100
60 / 100

Formability (cold)

25 / 100
30 / 100

Polishability

60 / 100
45 / 100

Brazeability / Solderability

—
30 / 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

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

204 kN·m/kg
185 kN·m/kg

Modulus of Resilience

4,024 kJ/m³
3,720 kJ/m³

Thermal Diffusivity

8.1 mm²/s
10.3 mm²/s

Thermal Shock Resistance Index

19
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 500NM450

Manufacturing and finishing

CapabilityHardox 500NM450
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 NM450 — frequently asked

Is Hardox 500 stronger than NM450?

Yes. Hardox 500 has a typical tensile strength of 1,600 MPa (232 ksi) against 1,450 MPa (210 ksi) for NM450 — about 10% more.

Which is cheaper, Hardox 500 or NM450?

NM450 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 NM450?

Hardox 500, by a small margin. Both rate poor for machinability — 22/100 against 15/100 for NM450; for welding the order is NM450 first (good, 60/100) then Hardox 500 (good, 55/100).

Ready to make it?

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