Steel Dillidur 400V QT-400HB-THICK vs Dillidur 400V-SR
Steel · Dillidur 400V temper comparison
Dillidur 400V QT-400HB-THICK and Dillidur 400V-SR are two conditions of the same steel grade, Dillidur 400V: QT-400HB-THICK (Q&T 400 HB, heavy plate) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Dillidur 400V-SR is the stronger of the two: yield strength 1,080 MPa (157 ksi) against 1,000 MPa (145 ksi) for Dillidur 400V QT-400HB-THICK, about 8% more. On the shop floor, Dillidur 400V-SR welds better (good vs fair) and Dillidur 400V-SR forms better (33 vs 22 out of 100).
Dillidur 400V-SRChoose it when strength drives the design, or when it will be welded.
Dillidur 400V QT-400HB-THICK vs Dillidur 400V-SR: 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.
Dillidur 400V QT-400HB-THICKDillidur 400V-SR
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Elongation at Break 11% · Reduction in Area 42% · Fracture Toughness (K_IC) 80 MPa·√m72.8 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Same in both: Thermal Conductivity 38 W/m·K22 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Max Service Temperature (continuous) 250°C482 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 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 %)
Weldability
Formability (cold)
Same in both: Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 25%
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.
Dillidur 400V QT-400HB-THICK vs Dillidur 400V-SR — frequently asked
Is Dillidur 400V-SR stronger than Dillidur 400V QT-400HB-THICK?
Yes. Dillidur 400V-SR has a typical yield strength of 1,080 MPa (157 ksi) against 1,000 MPa (145 ksi) for Dillidur 400V QT-400HB-THICK — about 8% more. Tensile strength is 1,220 MPa (177 ksi) vs 1,200 MPa (174 ksi).
Which condition does FabDigit quote by default, QT-400HB-THICK or SR?
QT-400HB is the default Dillidur 400V condition in the FabDigit quote flow (neither QT-400HB-THICK nor SR). 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 welds better, Dillidur 400V QT-400HB-THICK or Dillidur 400V-SR?
Dillidur 400V-SR. Its weldability rates good (58/100) against fair (48/100) for Dillidur 400V QT-400HB-THICK.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Dillidur 400V QT-400HB-THICK and Dillidur 400V-SR 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.