Steel HP9-4-20-ANN vs HP9-4-20 QT-LT
Steel · HP9-4-20 temper comparison
HP9-4-20-ANN and HP9-4-20 QT-LT are two conditions of the same steel grade, HP9-4-20: ANN (annealed) versus QT-LT (Q&T low temper). The chemistry is identical, so every difference below comes from the condition. HP9-4-20 QT-LT is the stronger of the two: yield strength 1,280 MPa (186 ksi) against 760 MPa (110 ksi) for HP9-4-20-ANN, about 68% more; tensile strength follows at 1,500 MPa (218 ksi) vs 965 MPa (140 ksi). In exchange, HP9-4-20-ANN is the more ductile: elongation 20% versus 14% for HP9-4-20 QT-LT, and HP9-4-20 QT-LT is harder (390 HB vs 280 HB). HP9-4-20-ANN runs hotter in service (400°C vs 175°C continuous). On the shop floor, HP9-4-20-ANN machines more easily (fair vs poor).
HP9-4-20-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
HP9-4-20 QT-LTChoose it when strength drives the design.
HP9-4-20-ANN vs HP9-4-20 QT-LT: 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 1,250 MPa181 ksi · Shear Strength 800 MPa116 ksi · Hardness, Vickers 410 HV
Physical
Density and transition temperatures.
Same in both: Density 7.83 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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 30 W/m·K17.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -100°C-148 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 15 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 70 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 42 MJ/kg18,057 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 20%
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.
HP9-4-20-ANN vs HP9-4-20 QT-LT — frequently asked
Is HP9-4-20 QT-LT stronger than HP9-4-20-ANN?
Yes. HP9-4-20 QT-LT has a typical yield strength of 1,280 MPa (186 ksi) against 760 MPa (110 ksi) for HP9-4-20-ANN — about 68% more. Tensile strength is 1,500 MPa (218 ksi) vs 965 MPa (140 ksi).
Which condition does FabDigit quote by default, ANN or QT-LT?
QT-190 is the default HP9-4-20 condition in the FabDigit quote flow (neither ANN nor QT-LT). 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, HP9-4-20-ANN or HP9-4-20 QT-LT?
HP9-4-20-ANN. Its machinability rates fair (42/100) against poor (28/100) for HP9-4-20 QT-LT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in HP9-4-20-ANN and HP9-4-20 QT-LT 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.