Nickel Alloy Alloy 689-HF vs Alloy 689-STA
Nickel Alloy · Alloy 689 temper comparison
Alloy 689-HF and Alloy 689-STA are two conditions of the same nickel alloy grade, Alloy 689: HF (as-hot-worked / as-forged) versus STA (solution treated and aged). The chemistry is identical, so every difference below comes from the condition. Alloy 689-STA is the stronger of the two: yield strength 840 MPa (122 ksi) against 690 MPa (100 ksi) for Alloy 689-HF, about 22% more; tensile strength follows at 1,240 MPa (180 ksi) vs 1,050 MPa (152 ksi). In exchange, Alloy 689-HF is the more ductile: elongation 24% versus 16% for Alloy 689-STA, and Alloy 689-STA is harder (331 HB vs 280 HB). Alloy 689-STA runs hotter in service (815°C vs 650°C continuous). On the shop floor, Alloy 689-HF welds better (fair vs poor).
Alloy 689-HFChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
Alloy 689-STAChoose it when strength drives the design, or when the part sees heat.
Alloy 689-HF vs Alloy 689-STA: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all nickel alloy 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 nickel alloy 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
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 172 GPa24.9 Msi · Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Same in both: Density 8.27 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,315°C2,399 °F · Liquidus Temperature 1,385°C2,525 °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 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 290 J/g125 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V
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 45 / 100 · Brazeability / Solderability 40 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 230 MJ/kg98,882 BTU/lb · Embodied Carbon (primary production) 15 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 30%
Strength versus weight
Yield strength against density for every nickel alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Alloy 689-HF vs Alloy 689-STA — frequently asked
Is Alloy 689-STA stronger than Alloy 689-HF?
Yes. Alloy 689-STA has a typical yield strength of 840 MPa (122 ksi) against 690 MPa (100 ksi) for Alloy 689-HF — about 22% more. Tensile strength is 1,240 MPa (180 ksi) vs 1,050 MPa (152 ksi).
Which condition does FabDigit quote by default, HF or STA?
STA is the default Alloy 689 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, Alloy 689-HF or Alloy 689-STA?
Alloy 689-HF. Its machinability rates poor (18/100) against not recommended (13/100) for Alloy 689-STA; for welding the order is Alloy 689-HF first (fair, 45/100) then Alloy 689-STA (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alloy 689-HF and Alloy 689-STA 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.