Steel Q355B-CR vs Q355B-HR
Steel · Q355B temper comparison
Q355B-CR and Q355B-HR are two conditions of the same steel grade, Q355B: CR (cold rolled) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. Q355B-CR is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 380 MPa (55.1 ksi) for Q355B-HR, about 11% more; tensile strength follows at 550 MPa (79.8 ksi) vs 520 MPa (75.4 ksi). In exchange, Q355B-HR is the more ductile: elongation 25% versus 20% for Q355B-CR, and Q355B-CR is harder (172 HB vs 155 HB).
Q355B-CRChoose it when strength drives the design.
Q355B-HRChoose it when the part is bent, formed or impact-loaded.
Q355B-CR vs Q355B-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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Reduction in Area 50% · Compressive Strength 380 MPa55.1 ksi · Shear Strength 340 MPa49.3 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in · Hardness, Vickers 163 HV
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,430°C2,606 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 48 W/m·K27.7 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8.6 % IACS · Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 14 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 60% · Weldability 85 / 100 · Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 22%
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.
Q355B-CR vs Q355B-HR — frequently asked
Is Q355B-CR stronger than Q355B-HR?
Yes. Q355B-CR has a typical yield strength of 420 MPa (60.9 ksi) against 380 MPa (55.1 ksi) for Q355B-HR — about 11% more. Tensile strength is 550 MPa (79.8 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, CR or HR?
HR is the default Q355B 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.
When should I choose Q355B-CR over Q355B-HR?
Pick Q355B-CR when strength drives the design. Pick Q355B-HR when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Q355B-CR and Q355B-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.