Steel G42CrMo4 +A vs G42CrMo4 +QT1
Steel · G42CrMo4 temper comparison
G42CrMo4 +A and G42CrMo4 +QT1 are two conditions of the same steel grade, G42CrMo4: +A (annealed) versus +QT1 (quenched and tempered, lower strength class). The chemistry is identical, so every difference below comes from the condition. G42CrMo4 +QT1 is the stronger of the two: yield strength 540 MPa (78.3 ksi) against 380 MPa (55.1 ksi) for G42CrMo4 +A, about 42% more; tensile strength follows at 780 MPa (113 ksi) vs 640 MPa (92.8 ksi). In exchange, G42CrMo4 +A is the more ductile: elongation 20% versus 14% for G42CrMo4 +QT1, and G42CrMo4 +QT1 is harder (235 HB vs 195 HB).
G42CrMo4 +AChoose it when the part is bent, formed or impact-loaded.
G42CrMo4 +QT1Choose it when strength drives the design.
G42CrMo4 +A vs G42CrMo4 +QT1: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Reduction in Area 40% · Compressive Strength 540 MPa78.3 ksi · Shear Strength 480 MPa69.6 ksi · Fracture Toughness (K_IC) 85 MPa·√m77.4 ksi·√in · Hardness, Rockwell C 21 HRC · Hardness, Vickers 245 HV
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 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 450°C842 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % 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 15 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Same in both: Formability (cold) 10 / 100 · Castability 60 / 100 · Brazeability / Solderability 50 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb · Typical Recycled Content 80%
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.
G42CrMo4 +A vs G42CrMo4 +QT1 — frequently asked
Is G42CrMo4 +QT1 stronger than G42CrMo4 +A?
Yes. G42CrMo4 +QT1 has a typical yield strength of 540 MPa (78.3 ksi) against 380 MPa (55.1 ksi) for G42CrMo4 +A — about 42% more. Tensile strength is 780 MPa (113 ksi) vs 640 MPa (92.8 ksi).
Which condition does FabDigit quote by default, +A or +QT1?
+QT1 is the default G42CrMo4 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, G42CrMo4 +A or G42CrMo4 +QT1?
G42CrMo4 +A. Its machinability rates good (58/100) against fair (50/100) for G42CrMo4 +QT1; for welding the order is G42CrMo4 +A first (fair, 40/100) then G42CrMo4 +QT1 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in G42CrMo4 +A and G42CrMo4 +QT1 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.