Steel HPM38-ANN vs HPM38 QT48-50
Steel · HPM38 temper comparison
HPM38-ANN and HPM38 QT48-50 are two conditions of the same steel grade, HPM38: ANN (annealed) versus QT48-50 (hardened & tempered 48–50 HRC). The chemistry is identical, so every difference below comes from the condition. HPM38 QT48-50 is the stronger of the two: yield strength 1,400 MPa (203 ksi) against 520 MPa (75.4 ksi) for HPM38-ANN, about 169% more; tensile strength follows at 1,650 MPa (239 ksi) vs 760 MPa (110 ksi). In exchange, HPM38-ANN is the more ductile: elongation 18% versus 6% for HPM38 QT48-50, and HPM38 QT48-50 is harder (49 HRC vs 18 HRC). HPM38-ANN runs hotter in service (400°C vs 200°C continuous). On the shop floor, HPM38-ANN machines more easily (fair vs poor).
HPM38-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
HPM38 QT48-50Choose it when strength drives the design.
HPM38-ANN vs HPM38 QT48-50: 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, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 45% · Shear Strength 460 MPa66.7 ksi · Hardness, Brinell 215 HB
Physical
Density and transition temperatures.
Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °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) 10.8 µm/m·K6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.35 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Polishability
Same in both: Weldability 25 / 100 · Formability (cold) 25 / 100 · Castability 20 / 100 · Brazeability / Solderability 30 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 52 MJ/kg22,356 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 40%
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.
HPM38-ANN vs HPM38 QT48-50 — frequently asked
Is HPM38 QT48-50 stronger than HPM38-ANN?
Yes. HPM38 QT48-50 has a typical yield strength of 1,400 MPa (203 ksi) against 520 MPa (75.4 ksi) for HPM38-ANN — about 169% more. Tensile strength is 1,650 MPa (239 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, ANN or QT48-50?
ANN is the default HPM38 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, HPM38-ANN or HPM38 QT48-50?
HPM38-ANN. Its machinability rates fair (45/100) against poor (18/100) for HPM38 QT48-50.
Ready to make it?
Upload a CAD file and FabDigit prices the part in HPM38-ANN and HPM38 QT48-50 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.