Steel L7-ANN vs L7-HR
Steel · L7 temper comparison
L7-ANN and L7-HR are two conditions of the same steel grade, L7: ANN (annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. L7-HR is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 415 MPa (60.2 ksi) for L7-ANN, about 25% more; tensile strength follows at 950 MPa (138 ksi) vs 750 MPa (109 ksi). In exchange, L7-ANN is the more ductile: elongation 25% versus 15% for L7-HR, and L7-HR is harder (260 HB vs 195 HB). L7-ANN runs hotter in service (250°C vs 200°C continuous). On the shop floor, L7-ANN machines more easily (fair vs poor).
L7-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
L7-HRChoose it when strength drives the design.
L7-ANN vs L7-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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 207 GPa30 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 7.84 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,470°C2,678 °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 460 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 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 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 %)
Weldability
Formability (cold)
Same in both: Castability 20 / 100 · Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 33 MJ/kg14,187 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 70 L/kg8.4 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.
L7-ANN vs L7-HR — frequently asked
Is L7-HR stronger than L7-ANN?
Yes. L7-HR has a typical yield strength of 520 MPa (75.4 ksi) against 415 MPa (60.2 ksi) for L7-ANN — about 25% more. Tensile strength is 950 MPa (138 ksi) vs 750 MPa (109 ksi).
Which condition does FabDigit quote by default, ANN or HR?
ANN is the default L7 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, L7-ANN or L7-HR?
L7-ANN. Its machinability rates fair (48/100) against poor (33/100) for L7-HR; for welding the order is L7-ANN first (poor, 15/100) then L7-HR (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in L7-ANN and L7-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.