Steel 20Cr-HR vs 20Cr-QT550
Steel · 20Cr temper comparison
20Cr-HR and 20Cr-QT550 are two conditions of the same steel grade, 20Cr: HR (hot rolled) versus QT550 (quenched + high tempered 500–600 °C). The chemistry is identical, so every difference below comes from the condition. 20Cr-QT550 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 380 MPa (55.1 ksi) for 20Cr-HR, about 45% more; tensile strength follows at 750 MPa (109 ksi) vs 600 MPa (87 ksi). In exchange, 20Cr-HR is the more ductile: elongation 22% versus 18% for 20Cr-QT550, and 20Cr-QT550 is harder (220 HB vs 170 HB).
20Cr-HRChoose it when the part is bent, formed or impact-loaded.
20Cr-QT550Choose it when strength drives the design.
20Cr-HR vs 20Cr-QT550: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 380 MPa55.1 ksi · Shear Strength 380 MPa55.1 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in · Hardness, Rockwell B 88 HRB
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 1,505°C2,741 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 55 / 100 · Formability (cold) 60 / 100 · Brazeability / Solderability 65 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%
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.
20Cr-HR vs 20Cr-QT550 — frequently asked
Is 20Cr-QT550 stronger than 20Cr-HR?
Yes. 20Cr-QT550 has a typical yield strength of 550 MPa (79.8 ksi) against 380 MPa (55.1 ksi) for 20Cr-HR — about 45% more. Tensile strength is 750 MPa (109 ksi) vs 600 MPa (87 ksi).
Which condition does FabDigit quote by default, HR or QT550?
HR is the default 20Cr condition in the FabDigit quote flow. 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, 20Cr-HR or 20Cr-QT550?
20Cr-HR, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 20Cr-QT550.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 20Cr-HR and 20Cr-QT550 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.