Steel SUM22 CH-Q vs SUM22-HR
Steel · SUM22 temper comparison
SUM22 CH-Q and SUM22-HR are two conditions of the same steel grade, SUM22: CH-Q (carburized, quenched and tempered) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. SUM22 CH-Q is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 250 MPa (36.3 ksi) for SUM22-HR, about 68% more; tensile strength follows at 620 MPa (89.9 ksi) vs 415 MPa (60.2 ksi). In exchange, SUM22-HR is the more ductile: elongation 25% versus 10% for SUM22 CH-Q, and SUM22 CH-Q is harder (160 HB vs 121 HB). SUM22-HR runs hotter in service (350°C vs 180°C continuous) and SUM22-HR conducts electricity better (10 % IACS vs 9 % IACS). On the shop floor, SUM22-HR machines more easily (excellent vs poor) and SUM22-HR welds better (poor vs not recommended).
SUM22 CH-QChoose it when strength drives the design.
SUM22-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
SUM22 CH-Q vs SUM22-HR: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.87 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 480 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 250 J/g107 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).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 8 / 100
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 60 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 35%
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.
SUM22 CH-Q vs SUM22-HR — frequently asked
Is SUM22 CH-Q stronger than SUM22-HR?
Yes. SUM22 CH-Q has a typical yield strength of 420 MPa (60.9 ksi) against 250 MPa (36.3 ksi) for SUM22-HR — about 68% more. Tensile strength is 620 MPa (89.9 ksi) vs 415 MPa (60.2 ksi).
Which condition does FabDigit quote by default, CH-Q or HR?
CD is the default SUM22 condition in the FabDigit quote flow (neither CH-Q nor HR). 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, SUM22 CH-Q or SUM22-HR?
SUM22-HR. Its machinability rates excellent (88/100) against poor (25/100) for SUM22 CH-Q; for welding the order is SUM22-HR first (poor, 25/100) then SUM22 CH-Q (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SUM22 CH-Q and SUM22-HR 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.