Steel D1-A vs D1-QT54
Steel · D1 temper comparison
D1-A and D1-QT54 are two conditions of the same steel grade, D1: A (solution annealed) versus QT54 (hardened & high-temperature tempered ~500–540 °C, 52–56 HRC). The chemistry is identical, so every difference below comes from the condition. D1-QT54 is the stronger of the two: yield strength 1,500 MPa (218 ksi) against 420 MPa (60.9 ksi) for D1-A, about 3.6 times as much; tensile strength follows at 1,750 MPa (254 ksi) vs 760 MPa (110 ksi). In exchange, D1-A is the more ductile: elongation 16% versus 3% for D1-QT54, and D1-QT54 is harder (580 HV vs 245 HV). D1-QT54 runs hotter in service (425°C vs 200°C continuous). On the shop floor, D1-A machines more easily (fair vs not recommended).
D1-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
D1-QT54Choose it when strength drives the design, or when the part sees heat.
D1-A vs D1-QT54: 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
Compressive Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Reduction in Area 30% · Shear Strength 480 MPa69.6 ksi · Fatigue Strength (Endurance Limit) 340 MPa49.3 ksi · Hardness, Brinell 235 HB · Hardness, Rockwell B 99 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,421°C2,590 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 20 W/m·K11.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.4 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.5×10⁻⁷ Ω·m25.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.45 V · Corrosion Resistance 28 / 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 15 / 100 · Formability (cold) 20 / 100 · Brazeability / Solderability 35 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 35 MJ/kg15,047 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 35%
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.
D1-A vs D1-QT54 — frequently asked
Is D1-QT54 stronger than D1-A?
Yes. D1-QT54 has a typical yield strength of 1,500 MPa (218 ksi) against 420 MPa (60.9 ksi) for D1-A — about 3.6 times as much. Tensile strength is 1,750 MPa (254 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, A or QT54?
A is the default D1 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, D1-A or D1-QT54?
D1-A. Its machinability rates fair (35/100) against not recommended (12/100) for D1-QT54.
Ready to make it?
Upload a CAD file and FabDigit prices the part in D1-A and D1-QT54 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.