Steel SMnB420H-CD vs SMnB420H-HR
Steel · SMnB420H temper comparison
SMnB420H-CD and SMnB420H-HR are two conditions of the same steel grade, SMnB420H: CD (cold drawn) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. SMnB420H-CD is the stronger of the two: yield strength 580 MPa (84.1 ksi) against 400 MPa (58 ksi) for SMnB420H-HR, about 45% more; tensile strength follows at 700 MPa (102 ksi) vs 620 MPa (89.9 ksi). In exchange, SMnB420H-HR is the more ductile: elongation 22% versus 12% for SMnB420H-CD, and SMnB420H-CD is harder (210 HB vs 187 HB). On the shop floor, SMnB420H-CD machines more easily (68 vs 58 out of 100).
SMnB420H-CDChoose it when strength drives the design, or when the part is machined in volume.
SMnB420H-HRChoose it when the part is bent, formed or impact-loaded.
SMnB420H-CD vs SMnB420H-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
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 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 340 MPa49.3 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in
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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
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) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8.2 % IACS · Electrical Resistivity 2.1×10⁻⁷ Ω·m8.27 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 55 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 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 kg CO₂/kg · Embodied Water 55 L/kg6.6 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.
SMnB420H-CD vs SMnB420H-HR — frequently asked
Is SMnB420H-CD stronger than SMnB420H-HR?
Yes. SMnB420H-CD has a typical yield strength of 580 MPa (84.1 ksi) against 400 MPa (58 ksi) for SMnB420H-HR — about 45% more. Tensile strength is 700 MPa (102 ksi) vs 620 MPa (89.9 ksi).
Which condition does FabDigit quote by default, CD or HR?
A is the default SMnB420H condition in the FabDigit quote flow (neither CD 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, SMnB420H-CD or SMnB420H-HR?
SMnB420H-CD, by a small margin. Both rate good for machinability — 68/100 against 58/100 for SMnB420H-HR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SMnB420H-CD and SMnB420H-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.