Steel 1.2738 Nitrided vs 1.2738 Q&T
Steel · 1.2738 temper comparison
1.2738 Nitrided and 1.2738 Q&T are two conditions of the same steel grade, 1.2738: Nitrided versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 1.2738 Q&T is the stronger of the two: yield strength 1,200 MPa (174 ksi) against 860 MPa (125 ksi) for 1.2738 Nitrided, about 40% more; tensile strength follows at 1,400 MPa (203 ksi) vs 1,000 MPa (145 ksi). In exchange, 1.2738 Nitrided is the more ductile: elongation 12% versus 10% for 1.2738 Q&T, and 1.2738 Q&T is harder (400 HB vs 305 HB). 1.2738 Nitrided runs hotter in service (450°C vs 350°C continuous). On the shop floor, 1.2738 Q&T machines more easily (poor vs not recommended) and 1.2738 Q&T welds better (poor vs not recommended).
1.2738 NitridedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.2738 Q&TChoose it when strength drives the design, or when the part is machined in volume.
1.2738 Nitrided vs 1.2738 Q&T: 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
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
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 · Shear Strength 620 MPa89.9 ksi
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 Q&T — frequently asked
Is 1.2738 Q&T stronger than 1.2738 Nitrided?
Yes. 1.2738 Q&T has a typical yield strength of 1,200 MPa (174 ksi) against 860 MPa (125 ksi) for 1.2738 Nitrided — about 40% more. Tensile strength is 1,400 MPa (203 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, Nitrided or Q&T?
Annealed is the default 1.2738 condition in the FabDigit quote flow (neither Nitrided nor Q&T). 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 Q&T?
1.2738 Q&T. Its machinability rates poor (30/100) against not recommended (8/100) for 1.2738 Nitrided; for welding the order is 1.2738 Q&T first (poor, 25/100) 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 Q&T 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.