Stainless Steel 420F Hardened & Tempered vs 420F Q&T 40-45 HRC
Stainless Steel · 420F temper comparison
420F Hardened & Tempered and 420F Q&T 40-45 HRC are two conditions of the same stainless steel grade, 420F: Hardened & Tempered (quenched and tempered) versus Q&T 40-45 HRC (oil quench, temper ≈500 °C). The chemistry is identical, so every difference below comes from the condition. 420F Hardened & Tempered is the stronger of the two: yield strength 1,480 MPa (215 ksi) against 1,180 MPa (171 ksi) for 420F Q&T 40-45 HRC, about 25% more; tensile strength follows at 1,720 MPa (249 ksi) vs 1,400 MPa (203 ksi). In exchange, 420F Q&T 40-45 HRC is the more ductile: elongation 11% versus 8% for 420F Hardened & Tempered, and 420F Hardened & Tempered is harder (480 HB vs 220 HB). 420F Q&T 40-45 HRC runs hotter in service (450°C vs 200°C continuous).
420F Hardened & TemperedChoose it when strength drives the design.
420F Q&T 40-45 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
420F Hardened & Tempered vs 420F Q&T 40-45 HRC: 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.
420F Hardened & Tempered420F Q&T 40-45 HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Hardness, Rockwell B 97 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.75 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 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °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) -0.3 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 12 / 100 · Castability 35 / 100 · Brazeability / Solderability 35 / 100 · Polishability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 45 MJ/kg19,347 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 65%
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.
420F Hardened & Tempered vs 420F Q&T 40-45 HRC — frequently asked
Is 420F Hardened & Tempered stronger than 420F Q&T 40-45 HRC?
Yes. 420F Hardened & Tempered has a typical yield strength of 1,480 MPa (215 ksi) against 1,180 MPa (171 ksi) for 420F Q&T 40-45 HRC — about 25% more. Tensile strength is 1,720 MPa (249 ksi) vs 1,400 MPa (203 ksi).
Which condition does FabDigit quote by default, Hardened & Tempered or Q&T 40-45 HRC?
Annealed is the default 420F condition in the FabDigit quote flow (neither Hardened & Tempered nor Q&T 40-45 HRC). 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, 420F Hardened & Tempered or 420F Q&T 40-45 HRC?
420F Q&T 40-45 HRC, by a small margin. Both rate poor for machinability — 28/100 against 22/100 for 420F Hardened & Tempered.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 420F Hardened & Tempered and 420F Q&T 40-45 HRC 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.