Steel P20 Annealed vs P20 Prehard-Nitrided
Steel · P20 temper comparison
P20 Annealed and P20 Prehard-Nitrided are two conditions of the same steel grade, P20: Annealed versus Prehard-Nitrided. The chemistry is identical, so every difference below comes from the condition. P20 Prehard-Nitrided is the stronger of the two: yield strength 860 MPa (125 ksi) against 440 MPa (63.8 ksi) for P20 Annealed, about 95% more; tensile strength follows at 1,000 MPa (145 ksi) vs 700 MPa (102 ksi). In exchange, P20 Annealed is the more ductile: elongation 20% versus 13% for P20 Prehard-Nitrided, and P20 Prehard-Nitrided is harder (300 HB vs 200 HB). On the shop floor, P20 Annealed machines more easily (good vs not recommended) and P20 Annealed welds better (fair vs not recommended).
P20 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
P20 Prehard-NitridedChoose it when strength drives the design.
P20 Annealed vs P20 Prehard-Nitrided: 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.
P20 AnnealedP20 Prehard-Nitrided
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 900 MPa131 ksi · Shear Strength 620 MPa89.9 ksi · Hardness, Rockwell B 93 HRB · Hardness, Rockwell C 31 HRC
Physical
Density and transition temperatures.
Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 32 W/m·K18.5 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.4 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 450°C842 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 40%
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.
P20 Annealed vs P20 Prehard-Nitrided — frequently asked
Is P20 Prehard-Nitrided stronger than P20 Annealed?
Yes. P20 Prehard-Nitrided has a typical yield strength of 860 MPa (125 ksi) against 440 MPa (63.8 ksi) for P20 Annealed — about 95% more. Tensile strength is 1,000 MPa (145 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, Annealed or Prehard-Nitrided?
Annealed is the default P20 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, P20 Annealed or P20 Prehard-Nitrided?
P20 Annealed. Its machinability rates good (65/100) against not recommended (10/100) for P20 Prehard-Nitrided; for welding the order is P20 Annealed first (fair, 50/100) then P20 Prehard-Nitrided (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in P20 Annealed and P20 Prehard-Nitrided 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.