Stainless Steel ER420-ANN vs ER420 QT-HARD
Stainless Steel · ER420 temper comparison
ER420-ANN and ER420 QT-HARD are two conditions of the same stainless steel grade, ER420: ANN (annealed) versus QT-HARD (Q&T). The chemistry is identical, so every difference below comes from the condition. ER420 QT-HARD is the stronger of the two: yield strength 1,550 MPa (225 ksi) against 450 MPa (65.3 ksi) for ER420-ANN, about 3.4 times as much; tensile strength follows at 1,850 MPa (268 ksi) vs 760 MPa (110 ksi). In exchange, ER420-ANN is the more ductile: elongation 18% versus 4% for ER420 QT-HARD, and ER420 QT-HARD is harder (500 HB vs 215 HB). ER420-ANN runs hotter in service (600°C vs 180°C continuous). On the shop floor, ER420-ANN machines more easily (fair vs not recommended).
ER420-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
ER420 QT-HARDChoose it when strength drives the design.
ER420-ANN vs ER420 QT-HARD: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Compressive Strength 1,700 MPa247 ksi · Shear Strength 990 MPa144 ksi · Fracture Toughness (K_IC) 20 MPa·√m18.2 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 24.9 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.3 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.25 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 35 / 100 · Brazeability / Solderability 45 / 100 · Polishability 80 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4.6 kg CO₂/kg · Embodied Water 180 L/kg21.6 gal/lb · Typical Recycled Content 55%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
ER420-ANN vs ER420 QT-HARD — frequently asked
Is ER420 QT-HARD stronger than ER420-ANN?
Yes. ER420 QT-HARD has a typical yield strength of 1,550 MPa (225 ksi) against 450 MPa (65.3 ksi) for ER420-ANN — about 3.4 times as much. Tensile strength is 1,850 MPa (268 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, ANN or QT-HARD?
AW is the default ER420 condition in the FabDigit quote flow (neither ANN nor QT-HARD). 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, ER420-ANN or ER420 QT-HARD?
ER420-ANN. Its machinability rates fair (42/100) against not recommended (10/100) for ER420 QT-HARD.
Ready to make it?
Upload a CAD file and FabDigit prices the part in ER420-ANN and ER420 QT-HARD 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.