Steel 38Cr2 +A vs 38Cr2 +QT
Steel · 38Cr2 temper comparison
38Cr2 +A and 38Cr2 +QT are two conditions of the same steel grade, 38Cr2: +A (annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 38Cr2 +QT is the stronger of the two: yield strength 560 MPa (81.2 ksi) against 360 MPa (52.2 ksi) for 38Cr2 +A, about 56% more; tensile strength follows at 800 MPa (116 ksi) vs 620 MPa (89.9 ksi). In exchange, 38Cr2 +A is the more ductile: elongation 21% versus 15% for 38Cr2 +QT, and 38Cr2 +QT is harder (240 HB vs 195 HB). On the shop floor, 38Cr2 +A machines more easily (good vs fair) and 38Cr2 +A welds better (48 vs 35 out of 100).
38Cr2 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
38Cr2 +QTChoose it when strength drives the design.
38Cr2 +A vs 38Cr2 +QT: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 560 MPa81.2 ksi · Shear Strength 480 MPa69.6 ksi · Fracture Toughness (K_IC) 75 MPa·√m68.3 ksi·√in · Hardness, Rockwell C 23 HRC
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 465 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 270 J/g116 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -25°C-13 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 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) -0.6 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: Castability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 30%
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.
38Cr2 +A vs 38Cr2 +QT — frequently asked
Is 38Cr2 +QT stronger than 38Cr2 +A?
Yes. 38Cr2 +QT has a typical yield strength of 560 MPa (81.2 ksi) against 360 MPa (52.2 ksi) for 38Cr2 +A — about 56% more. Tensile strength is 800 MPa (116 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, +A or +QT?
+QT is the default 38Cr2 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, 38Cr2 +A or 38Cr2 +QT?
38Cr2 +A. Its machinability rates good (63/100) against fair (50/100) for 38Cr2 +QT; for welding the order is 38Cr2 +A first (fair, 48/100) then 38Cr2 +QT (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 38Cr2 +A and 38Cr2 +QT 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.