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Steel 718H vs NAK80

Steel · grade comparison

Steel 718H and NAK80 are both steel grades, both mold steel. 718H is the stronger of the two: yield strength 900 MPa (131 ksi) against 700 MPa (102 ksi) for NAK80, about 29% more; tensile strength follows at 1,080 MPa (157 ksi) vs 900 MPa (131 ksi). In exchange, NAK80 is the more ductile: elongation 18% versus 13% for 718H, and 718H is harder (300 HB vs 270 HB). 718H runs hotter in service (450°C vs 400°C continuous). On the shop floor, NAK80 machines more easily (very good vs fair) and NAK80 welds better (50 vs 40 out of 100).

718HChoose it when strength drives the design, or when the part sees heat.

NAK80Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

718H vs NAK80: properties

718HNAK80

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

160 GPa23.2 Msi
162 GPa23.5 Msi

Tensile Strength (Ultimate)

1,080 MPa157 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

900 MPa131 ksi
700 MPa102 ksi

Elongation at Break

13%
18%

Shear Strength

650 MPa94.3 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

500 MPa72.5 ksi
600 MPa87 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

22 J16.2 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

300 HB
270 HB

Hardness, Rockwell C

32 HRC
28 HRC

Hardness, Vickers

320 HV
400 HV

Compressive Strength

—
1,200 MPa174 ksi

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Reduction in Area 45%

Physical

Density and transition temperatures.

Liquidus Temperature

1,480°C2,696 °F
—

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

450°C842 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
3×10⁻⁷ Ω·m11.8 µΩ·in

Electrical Conductivity

—
5.7 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
20 / 100

Manufacturability

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

Machinability

48 / 100
70 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
65%

Weldability

40 / 100
50 / 100

Formability (cold)

10 / 100
30 / 100

Polishability

80 / 100
75 / 100

Same in both: Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
36 MJ/kg15,477 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.6 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Typical Recycled Content

35%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

138 kN·m/kg
115 kN·m/kg

Modulus of Resilience

1,976 kJ/m³
1,195 kJ/m³

Thermal Diffusivity

9.2 mm²/s
8.4 mm²/s

Thermal Shock Resistance Index

14
11

Same in both: Specific Stiffness (E / density) 26.3 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 scale718HNAK80

Manufacturing and finishing

Capability718HNAK80
Default conditionPrehardAnnealed
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

718H vs NAK80 — frequently asked

Is 718H stronger than NAK80?

Yes. 718H has a typical yield strength of 900 MPa (131 ksi) against 700 MPa (102 ksi) for NAK80 — about 29% more. Tensile strength is 1,080 MPa (157 ksi) vs 900 MPa (131 ksi).

Which is cheaper, 718H or NAK80?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 718H or NAK80?

NAK80. Its machinability rates very good (70/100) against fair (48/100) for 718H; for welding the order is NAK80 first (fair, 50/100) then 718H (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 718H and NAK80 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.