Steel 1.2738 Annealed vs 1.2738 Prehard
Steel · 1.2738 temper comparison
1.2738 Annealed and 1.2738 Prehard are two conditions of the same steel grade, 1.2738: Annealed versus Prehard (pre-hardened). The chemistry is identical, so every difference below comes from the condition. 1.2738 Prehard is the stronger of the two: yield strength 860 MPa (125 ksi) against 470 MPa (68.2 ksi) for 1.2738 Annealed, about 83% more; tensile strength follows at 1,000 MPa (145 ksi) vs 760 MPa (110 ksi). In exchange, 1.2738 Annealed is the more ductile: elongation 20% versus 14% for 1.2738 Prehard, and 1.2738 Prehard is harder (305 HB vs 220 HB). On the shop floor, 1.2738 Annealed machines more easily (65 vs 55 out of 100).
1.2738 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
1.2738 PrehardChoose it when strength drives the design.
1.2738 Annealed 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Fatigue Strength (Endurance Limit)
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 · Compressive Strength 880 MPa128 ksi · Shear Strength 620 MPa89.9 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in
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.
Same in both: Thermal Conductivity 33 W/m·K19.1 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 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 50 / 100 · Formability (cold) 30 / 100 · 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 Annealed vs 1.2738 Prehard — frequently asked
Is 1.2738 Prehard stronger than 1.2738 Annealed?
Yes. 1.2738 Prehard has a typical yield strength of 860 MPa (125 ksi) against 470 MPa (68.2 ksi) for 1.2738 Annealed — about 83% more. Tensile strength is 1,000 MPa (145 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, Annealed or Prehard?
Annealed is the default 1.2738 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, 1.2738 Annealed or 1.2738 Prehard?
1.2738 Annealed, by a small margin. Both rate good for machinability — 65/100 against 55/100 for 1.2738 Prehard.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.2738 Annealed 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.