Stainless Steel 420C-H vs 420C QT 50-55 HRC
Stainless Steel · 420C temper comparison
420C-H and 420C QT 50-55 HRC are two conditions of the same stainless steel grade, 420C: H (hardened) versus QT 50-55 HRC. The chemistry is identical, so every difference below comes from the condition. 420C-H is the stronger of the two: tensile strength 1,950 MPa (283 ksi) against 1,800 MPa (261 ksi) for 420C QT 50-55 HRC, about 8% more. In exchange, 420C QT 50-55 HRC is the more ductile: elongation 3% versus 1% for 420C-H, and 420C-H is harder (615 HB vs 220 HB). 420C QT 50-55 HRC runs hotter in service (250°C vs 200°C continuous) and 420C QT 50-55 HRC conducts heat better (30 W/m·K vs 24 W/m·K). On the shop floor, 420C QT 50-55 HRC welds better (poor vs not recommended).
420C-HChoose it when strength drives the design.
420C QT 50-55 HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
420C-H vs 420C QT 50-55 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.
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 C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 215 GPa31.2 Msi · Shear Modulus 83 GPa12 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 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °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 -20°C-4 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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: Castability 40 / 100 · Brazeability / Solderability 45 / 100 · Polishability 78 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 50 MJ/kg21,496 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 45%
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.
420C-H vs 420C QT 50-55 HRC — frequently asked
Is 420C-H stronger than 420C QT 50-55 HRC?
Yes. 420C-H has a typical tensile strength of 1,950 MPa (283 ksi) against 1,800 MPa (261 ksi) for 420C QT 50-55 HRC — about 8% more.
Which condition does FabDigit quote by default, H or QT 50-55 HRC?
+A is the default 420C condition in the FabDigit quote flow (neither H nor QT 50-55 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, 420C-H or 420C QT 50-55 HRC?
420C QT 50-55 HRC. Its weldability rates poor (20/100) against not recommended (5/100) for 420C-H.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 420C-H and 420C QT 50-55 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.