Steel Alloy 79 Annealed vs Alloy 79 HR-ANN
Steel · Alloy 79 temper comparison
Alloy 79 Annealed and Alloy 79 HR-ANN are two conditions of the same steel grade, Alloy 79: Annealed versus HR-ANN (hot Rolled + Annealed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 270 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Annealed versus hot Rolled + Annealed). Alloy 79 HR-ANN is harder — 130 HB against 120 HB for Alloy 79 Annealed — which matters for wear surfaces and threads.
Alloy 79 HR-ANNChoose it when surface hardness matters.
Alloy 79 Annealed vs Alloy 79 HR-ANN: 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.
Alloy 79 AnnealedAlloy 79 HR-ANN
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
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 205 GPa29.7 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 172 GPa24.9 Msi · Poisson's Ratio 0.3 · Reduction in Area 60%
Physical
Density and transition temperatures.
Same in both: Density 8.74 g/cm³0.32 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 30 W/m·K17.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.7 µm/m·K7.1 µin/in·°F · Latent Heat of Fusion 290 J/g125 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3 % IACS · Electrical Resistivity 5.7×10⁻⁷ Ω·m22.4 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.2 V · Corrosion Resistance 50 / 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 60 / 100 · Brazeability / Solderability 70 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 115 MJ/kg49,441 BTU/lb · Embodied Carbon (primary production) 11 kg CO₂/kg · Embodied Water 400 L/kg47.9 gal/lb · Typical Recycled Content 25%
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.
Alloy 79 Annealed vs Alloy 79 HR-ANN — frequently asked
What is the difference between Alloy 79 Annealed and Alloy 79 HR-ANN?
Alloy 79 Annealed and Alloy 79 HR-ANN are two conditions of the same steel grade, Alloy 79: Annealed versus HR-ANN (hot Rolled + Annealed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 270 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Annealed versus hot Rolled + Annealed).
Which condition does FabDigit quote by default, Annealed or HR-ANN?
Annealed is the default Alloy 79 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 Alloy 79 Annealed over Alloy 79 HR-ANN?
Pick Alloy 79 HR-ANN when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alloy 79 Annealed and Alloy 79 HR-ANN 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.