Steel A536 120-90-02-QT vs A536 120-90-02 QT-HH
Steel · A536 120-90-02 temper comparison
A536 120-90-02-QT and A536 120-90-02 QT-HH are two conditions of the same steel grade, A536 120-90-02: QT (quenched and tempered) versus QT-HH (quenched and low-temperature tempered, high hardness). The chemistry is identical, so every difference below comes from the condition. A536 120-90-02 QT-HH is the stronger of the two: yield strength 750 MPa (109 ksi) against 660 MPa (95.7 ksi) for A536 120-90-02-QT, about 14% more; tensile strength follows at 1,000 MPa (145 ksi) vs 900 MPa (131 ksi). In exchange, A536 120-90-02-QT is the more ductile: elongation 3% versus 2% for A536 120-90-02 QT-HH, and A536 120-90-02 QT-HH is harder (360 HB vs 302 HB). A536 120-90-02-QT runs hotter in service (350°C vs 250°C continuous) and A536 120-90-02-QT conducts heat better (32 W/m·K vs 28 W/m·K). On the shop floor, A536 120-90-02-QT machines more easily (fair vs poor).
A536 120-90-02-QTChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A536 120-90-02 QT-HHChoose it when strength drives the design.
A536 120-90-02-QT vs A536 120-90-02 QT-HH: 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.
A536 120-90-02-QTA536 120-90-02 QT-HH
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
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: Shear Modulus 66 GPa9.6 Msi · Bulk Modulus 138 GPa20 Msi · Poisson's Ratio 0.28
Physical
Density and transition temperatures.
Same in both: Density 7.1 g/cm³0.26 lb/in³ · Melting Point (Solidus) 1,140°C2,084 °F · Liquidus Temperature 1,165°C2,129 °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) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 16 / 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: Castability 82 / 100 · Brazeability / Solderability 30 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 21 MJ/kg9,028 BTU/lb · Embodied Carbon (primary production) 1.8 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 85%
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.
A536 120-90-02-QT vs A536 120-90-02 QT-HH — frequently asked
Is A536 120-90-02 QT-HH stronger than A536 120-90-02-QT?
Yes. A536 120-90-02 QT-HH has a typical yield strength of 750 MPa (109 ksi) against 660 MPa (95.7 ksi) for A536 120-90-02-QT — about 14% more. Tensile strength is 1,000 MPa (145 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, QT or QT-HH?
QT is the default A536 120-90-02 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, A536 120-90-02-QT or A536 120-90-02 QT-HH?
A536 120-90-02-QT. Its machinability rates fair (35/100) against poor (25/100) for A536 120-90-02 QT-HH; for welding the order is A536 120-90-02-QT first (poor, 18/100) then A536 120-90-02 QT-HH (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A536 120-90-02-QT and A536 120-90-02 QT-HH 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.