Steel 1.2738 Nitrided vs 1.2738 Prehard
Steel · 1.2738 temper comparison
1.2738 Nitrided and 1.2738 Prehard are two conditions of the same steel grade, 1.2738: Nitrided versus Prehard (pre-hardened). The chemistry is identical, so every difference below comes from the condition. Both yield at about 860 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Nitrided versus pre-hardened). 1.2738 Prehard is the more ductile: elongation 14% versus 12% for 1.2738 Nitrided, and 1.2738 Nitrided is harder (950 HV vs 320 HV). 1.2738 Nitrided runs hotter in service (450°C vs 400°C continuous). On the shop floor, 1.2738 Prehard machines more easily (good vs not recommended) and 1.2738 Prehard welds better (fair vs not recommended).
1.2738 NitridedChoose it when the part sees heat.
1.2738 PrehardChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1.2738 Nitrided vs 1.2738 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.
Elongation at Break
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
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 · Tensile Strength (Ultimate) 1,000 MPa145 ksi · Yield Strength (0.2% offset) 860 MPa125 ksi · Shear Strength 620 MPa89.9 ksi · Hardness, Brinell 305 HB · 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 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: 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 270 J/g116 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 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 78 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
1.2738 Nitrided vs 1.2738 Prehard — frequently asked
What is the difference between 1.2738 Nitrided and 1.2738 Prehard?
1.2738 Nitrided and 1.2738 Prehard are two conditions of the same steel grade, 1.2738: Nitrided versus Prehard (pre-hardened). The chemistry is identical, so every difference below comes from the condition. Both yield at about 860 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Nitrided versus pre-hardened).
Which condition does FabDigit quote by default, Nitrided or Prehard?
Annealed is the default 1.2738 condition in the FabDigit quote flow (neither Nitrided nor Prehard). 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, 1.2738 Nitrided or 1.2738 Prehard?
1.2738 Prehard. Its machinability rates good (55/100) against not recommended (8/100) for 1.2738 Nitrided; for welding the order is 1.2738 Prehard first (fair, 50/100) then 1.2738 Nitrided (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.2738 Nitrided and 1.2738 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.