Steel NAK80 Annealed vs NAK80 Prehard
Steel · NAK80 temper comparison
NAK80 Annealed and NAK80 Prehard are two conditions of the same steel grade, NAK80: Annealed versus Prehard (pre-hardened). The chemistry is identical, so every difference below comes from the condition. NAK80 Prehard is the stronger of the two: yield strength 1,150 MPa (167 ksi) against 700 MPa (102 ksi) for NAK80 Annealed, about 64% more; tensile strength follows at 1,300 MPa (189 ksi) vs 900 MPa (131 ksi). In exchange, NAK80 Annealed is the more ductile: elongation 18% versus 12% for NAK80 Prehard, and NAK80 Prehard is harder (40 HRC vs 28 HRC). On the shop floor, NAK80 Annealed machines more easily (very good vs good).
NAK80 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
NAK80 PrehardChoose it when strength drives the design.
NAK80 Annealed vs NAK80 Prehard: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 162 GPa23.5 Msi · Poisson's Ratio 0.29 · Reduction in Area 45% · Compressive Strength 1,200 MPa174 ksi · Shear Strength 780 MPa113 ksi · Fatigue Strength (Endurance Limit) 600 MPa87 ksi · Fracture Toughness (K_IC) 60 MPa·√m54.6 ksi·√in · Hardness, Brinell 270 HB · Hardness, Vickers 400 HV
Physical
Density and transition temperatures.
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.
Same in both: Thermal Conductivity 30 W/m·K17.3 BTU/hr·ft·°F · 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 · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 5.7 % IACS · Electrical Resistivity 3×10⁻⁷ Ω·m11.8 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 20 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Polishability
Same in both: Weldability 50 / 100 · Formability (cold) 30 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 65 L/kg7.8 gal/lb · Typical Recycled Content 30%
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.
NAK80 Annealed vs NAK80 Prehard — frequently asked
Is NAK80 Prehard stronger than NAK80 Annealed?
Yes. NAK80 Prehard has a typical yield strength of 1,150 MPa (167 ksi) against 700 MPa (102 ksi) for NAK80 Annealed — about 64% more. Tensile strength is 1,300 MPa (189 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, Annealed or Prehard?
Annealed is the default NAK80 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, NAK80 Annealed or NAK80 Prehard?
NAK80 Annealed. Its machinability rates very good (70/100) against good (55/100) for NAK80 Prehard.
Ready to make it?
Upload a CAD file and FabDigit prices the part in NAK80 Annealed and NAK80 Prehard 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.