Steel G20Mn5-AC vs G20Mn5 +QT
Steel · G20Mn5 temper comparison
G20Mn5-AC and G20Mn5 +QT are two conditions of the same steel grade, G20Mn5: AC (spheroidize annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. G20Mn5 +QT is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 280 MPa (40.6 ksi) for G20Mn5-AC, about 36% more; tensile strength follows at 580 MPa (84.1 ksi) vs 520 MPa (75.4 ksi). G20Mn5 +QT is the more ductile: elongation 26% versus 16% for G20Mn5-AC, and G20Mn5 +QT is harder (180 HB vs 160 HB). G20Mn5 +QT runs hotter in service (400°C vs 350°C continuous).
G20Mn5 +QTChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
G20Mn5-AC vs G20Mn5 +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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 48 W/m·K27.7 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
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 11 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Same in both: Machinability 54 / 100 · Machinability Rating (AISI 1212 = 100 %) 55% · Castability 75 / 100 · Brazeability / Solderability 55 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 55 L/kg6.6 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.
G20Mn5-AC vs G20Mn5 +QT — frequently asked
Is G20Mn5 +QT stronger than G20Mn5-AC?
Yes. G20Mn5 +QT has a typical yield strength of 380 MPa (55.1 ksi) against 280 MPa (40.6 ksi) for G20Mn5-AC — about 36% more. Tensile strength is 580 MPa (84.1 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, AC or +QT?
+N is the default G20Mn5 condition in the FabDigit quote flow (neither AC nor +QT). 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.
When should I choose G20Mn5-AC over G20Mn5 +QT?
Pick G20Mn5 +QT when strength drives the design, or when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in G20Mn5-AC and G20Mn5 +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.