Steel A4-ANN vs A4 HT57-59
Steel · A4 temper comparison
A4-ANN and A4 HT57-59 are two conditions of the same steel grade, A4: ANN (annealed) versus HT57-59 (hardened & tempered 57–59 HRC). The chemistry is identical, so every difference below comes from the condition. A4 HT57-59 is the stronger of the two: yield strength 1,700 MPa (247 ksi) against 415 MPa (60.2 ksi) for A4-ANN, about 4.1 times as much; tensile strength follows at 1,950 MPa (283 ksi) vs 745 MPa (108 ksi). In exchange, A4-ANN is the more ductile: elongation 20% versus 2.5% for A4 HT57-59, and A4 HT57-59 is harder (660 HV vs 235 HV). A4-ANN runs hotter in service (400°C vs 230°C continuous). On the shop floor, A4-ANN machines more easily (good vs not recommended) and A4-ANN welds better (poor vs not recommended).
A4-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A4 HT57-59Choose it when strength drives the design.
A4-ANN vs A4 HT57-59: 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.
Elastic (Young's) Modulus
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, Vickers
Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 225 HB · Hardness, Rockwell B 98 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.8 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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 25 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.4×10⁻⁷ Ω·m25.2 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 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)
Polishability
Same in both: Castability 20 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.8 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 45%
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.
A4-ANN vs A4 HT57-59 — frequently asked
Is A4 HT57-59 stronger than A4-ANN?
Yes. A4 HT57-59 has a typical yield strength of 1,700 MPa (247 ksi) against 415 MPa (60.2 ksi) for A4-ANN — about 4.1 times as much. Tensile strength is 1,950 MPa (283 ksi) vs 745 MPa (108 ksi).
Which condition does FabDigit quote by default, ANN or HT57-59?
ANN is the default A4 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, A4-ANN or A4 HT57-59?
A4-ANN. Its machinability rates good (55/100) against not recommended (6/100) for A4 HT57-59; for welding the order is A4-ANN first (poor, 25/100) then A4 HT57-59 (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A4-ANN and A4 HT57-59 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.