Steel D1-QT54 vs D1-QT58
Steel · D1 temper comparison
D1-QT54 and D1-QT58 are two conditions of the same steel grade, D1: QT54 (hardened & high-temperature tempered ~500–540 °C, 52–56 HRC) versus QT58 (hardened & tempered ~200–260 °C, 57–59 HRC). The chemistry is identical, so every difference below comes from the condition. D1-QT58 is the stronger of the two: yield strength 1,600 MPa (232 ksi) against 1,500 MPa (218 ksi) for D1-QT54, about 7% more; tensile strength follows at 1,900 MPa (276 ksi) vs 1,750 MPa (254 ksi). In exchange, D1-QT54 is the more ductile: elongation 3% versus 2% for D1-QT58, and D1-QT58 is harder (660 HV vs 580 HV). D1-QT54 runs hotter in service (425°C vs 225°C continuous).
D1-QT54Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
D1-QT58Choose it when strength drives the design.
D1-QT54 vs D1-QT58: 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
Fatigue Strength (Endurance Limit)
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 · 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-QT54 vs D1-QT58 — frequently asked
Is D1-QT58 stronger than D1-QT54?
Yes. D1-QT58 has a typical yield strength of 1,600 MPa (232 ksi) against 1,500 MPa (218 ksi) for D1-QT54 — about 7% more. Tensile strength is 1,900 MPa (276 ksi) vs 1,750 MPa (254 ksi).
Which condition does FabDigit quote by default, QT54 or QT58?
A is the default D1 condition in the FabDigit quote flow (neither QT54 nor QT58). 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.
When should I choose D1-QT54 over D1-QT58?
Pick D1-QT54 when the part is bent, formed or impact-loaded, or when the part sees heat. Pick D1-QT58 when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in D1-QT54 and D1-QT58 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.