Stainless Steel 420J2 Hardened & Tempered vs 420J2 Q&T 45-50 HRC
Stainless Steel · 420J2 temper comparison
420J2 Hardened & Tempered and 420J2 Q&T 45-50 HRC are two conditions of the same stainless steel grade, 420J2: Hardened & Tempered (quenched and tempered) versus Q&T 45-50 HRC (quenched and tempered ≈ 300–350 °C). The chemistry is identical, so every difference below comes from the condition. 420J2 Hardened & Tempered is the stronger of the two: yield strength 1,450 MPa (210 ksi) against 1,300 MPa (189 ksi) for 420J2 Q&T 45-50 HRC, about 12% more; tensile strength follows at 1,720 MPa (249 ksi) vs 1,550 MPa (225 ksi). In exchange, 420J2 Q&T 45-50 HRC is the more ductile: elongation 8% versus 6% for 420J2 Hardened & Tempered, and 420J2 Hardened & Tempered is harder (520 HV vs 480 HV). 420J2 Q&T 45-50 HRC runs hotter in service (300°C vs 250°C continuous). On the shop floor, 420J2 Q&T 45-50 HRC welds better (25 vs 15 out of 100).
420J2 Hardened & TemperedChoose it when strength drives the design.
420J2 Q&T 45-50 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
420J2 Hardened & Tempered vs 420J2 Q&T 45-50 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.
420J2 Hardened & Tempered420J2 Q&T 45-50 HRC
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)
Charpy V-Notch Impact (RT)
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 0.29 · Hardness, Brinell 220 HB · Hardness, Rockwell B 96 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.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 260 J/g112 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) -0.35 V
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: Brazeability / Solderability 40 / 100 · Polishability 85 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 45 MJ/kg19,347 BTU/lb · Embodied Carbon (primary production) 3.2 kg CO₂/kg · Embodied Water 110 L/kg13.2 gal/lb · Typical Recycled Content 60%
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.
420J2 Hardened & Tempered vs 420J2 Q&T 45-50 HRC — frequently asked
Is 420J2 Hardened & Tempered stronger than 420J2 Q&T 45-50 HRC?
Yes. 420J2 Hardened & Tempered has a typical yield strength of 1,450 MPa (210 ksi) against 1,300 MPa (189 ksi) for 420J2 Q&T 45-50 HRC — about 12% more. Tensile strength is 1,720 MPa (249 ksi) vs 1,550 MPa (225 ksi).
Which condition does FabDigit quote by default, Hardened & Tempered or Q&T 45-50 HRC?
Annealed is the default 420J2 condition in the FabDigit quote flow (neither Hardened & Tempered nor Q&T 45-50 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 welds better, 420J2 Hardened & Tempered or 420J2 Q&T 45-50 HRC?
420J2 Q&T 45-50 HRC. Its weldability rates poor (25/100) against poor (15/100) for 420J2 Hardened & Tempered.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 420J2 Hardened & Tempered and 420J2 Q&T 45-50 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.