Steel C45 +A vs C45-HR
Steel · C45 temper comparison
C45 +A and C45-HR are two conditions of the same steel grade, C45: +A (annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. C45 +A is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 330 MPa (47.9 ksi) for C45-HR, about 6% more. C45 +A is the more ductile: elongation 22% versus 16% for C45-HR, and C45-HR is harder (175 HB vs 165 HB).
C45 +AChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
C45 +A vs C45-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.
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 B
Hardness, Vickers
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 · Tensile Strength (Ultimate) 585 MPa84.8 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 486 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 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 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 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 %)
Formability (cold)
Same in both: Weldability 45 / 100 · Castability 45 / 100 · Brazeability / Solderability 65 / 100 · Polishability 60 / 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 kg CO₂/kg · Embodied Water 50 L/kg6 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.
C45 +A vs C45-HR — frequently asked
Is C45 +A stronger than C45-HR?
Yes. C45 +A has a typical yield strength of 350 MPa (50.8 ksi) against 330 MPa (47.9 ksi) for C45-HR — about 6% more. Tensile strength is 585 MPa (84.8 ksi) vs 585 MPa (84.8 ksi).
Which condition does FabDigit quote by default, +A or HR?
Normalized is the default C45 condition in the FabDigit quote flow (neither +A 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, C45 +A or C45-HR?
C45 +A, by a small margin. Both rate good for machinability — 60/100 against 55/100 for C45-HR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in C45 +A and C45-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.