Steel HP9-4-20 N+T vs HP9-4-20 QT-190
Steel · HP9-4-20 temper comparison
HP9-4-20 N+T and HP9-4-20 QT-190 are two conditions of the same steel grade, HP9-4-20: N+T (normalized and tempered) versus QT-190 (Q&T 190 ksi). The chemistry is identical, so every difference below comes from the condition. HP9-4-20 QT-190 is the stronger of the two: yield strength 1,210 MPa (175 ksi) against 930 MPa (135 ksi) for HP9-4-20 N+T, about 30% more; tensile strength follows at 1,340 MPa (194 ksi) vs 1,100 MPa (160 ksi). In exchange, HP9-4-20 N+T is the more ductile: elongation 19% versus 17% for HP9-4-20 QT-190, and HP9-4-20 QT-190 is harder (390 HB vs 320 HB).
HP9-4-20 N+TChoose it when the part is bent, formed or impact-loaded.
HP9-4-20 QT-190Choose it when strength drives the design.
HP9-4-20 N+T vs HP9-4-20 QT-190: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
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
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.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: 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.
Electrical Resistivity
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 %)
Weldability
Formability (cold)
Same in both: 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 N+T vs HP9-4-20 QT-190 — frequently asked
Is HP9-4-20 QT-190 stronger than HP9-4-20 N+T?
Yes. HP9-4-20 QT-190 has a typical yield strength of 1,210 MPa (175 ksi) against 930 MPa (135 ksi) for HP9-4-20 N+T — about 30% more. Tensile strength is 1,340 MPa (194 ksi) vs 1,100 MPa (160 ksi).
Which condition does FabDigit quote by default, N+T or QT-190?
QT-190 is the default HP9-4-20 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, HP9-4-20 N+T or HP9-4-20 QT-190?
HP9-4-20 N+T. Its machinability rates fair (35/100) against poor (28/100) for HP9-4-20 QT-190; for welding the order is HP9-4-20 N+T first (very good, 75/100) then HP9-4-20 QT-190 (very good, 70/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HP9-4-20 N+T and HP9-4-20 QT-190 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.