Precious Metal Gold 18K-1/2 Hard vs Gold 18K Stress Relieved
Precious Metal · Gold 18K temper comparison
Gold 18K-1/2 Hard and Gold 18K Stress Relieved are two conditions of the same precious metal grade, Gold 18K: 1/2 Hard (half hard) versus Stress Relieved. The chemistry is identical, so every difference below comes from the condition. Gold 18K Stress Relieved is the stronger of the two: yield strength 580 MPa (84.1 ksi) against 500 MPa (72.5 ksi) for Gold 18K-1/2 Hard, about 16% more; tensile strength follows at 700 MPa (102 ksi) vs 640 MPa (92.8 ksi). In exchange, Gold 18K-1/2 Hard is the more ductile: elongation 10% versus 9% for Gold 18K Stress Relieved, and Gold 18K Stress Relieved is harder (205 HB vs 190 HB).
Gold 18K-1/2 HardChoose it when the part is bent, formed or impact-loaded.
Gold 18K Stress RelievedChoose it when strength drives the design.
Gold 18K-1/2 Hard vs Gold 18K Stress Relieved: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all precious metal 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 precious metal 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.
Gold 18K-1/2 HardGold 18K Stress Relieved
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)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 79 GPa11.5 Msi · Shear Modulus 28 GPa4.1 Msi · Bulk Modulus 135 GPa19.6 Msi · Poisson's Ratio 0.39
Physical
Density and transition temperatures.
Same in both: Density 15.5 g/cm³0.56 lb/in³ · Melting Point (Solidus) 895°C1,643 °F · Liquidus Temperature 920°C1,688 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 180 W/m·K104 BTU/hr·ft·°F · Specific Heat Capacity 165 J/kg·K0.04 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16 µm/m·K8.9 µin/in·°F · Latent Heat of Fusion 80 J/g34.4 BTU/lb · Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 15 % IACS · Electrical Resistivity 1.15×10⁻⁷ Ω·m4.53 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) 0.25 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 85 / 100 · Brazeability / Solderability 95 / 100 · Polishability 98 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 180,000 MJ/kg7.74×10⁷ BTU/lb · Embodied Carbon (primary production) 11,000 kg CO₂/kg · Embodied Water 100,000 L/kg11,983 gal/lb · Typical Recycled Content 30%
Strength versus weight
Yield strength against density for every precious metal grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Gold 18K-1/2 Hard vs Gold 18K Stress Relieved — frequently asked
Is Gold 18K Stress Relieved stronger than Gold 18K-1/2 Hard?
Yes. Gold 18K Stress Relieved has a typical yield strength of 580 MPa (84.1 ksi) against 500 MPa (72.5 ksi) for Gold 18K-1/2 Hard — about 16% more. Tensile strength is 700 MPa (102 ksi) vs 640 MPa (92.8 ksi).
Which condition does FabDigit quote by default, 1/2 Hard or Stress Relieved?
O is the default Gold 18K condition in the FabDigit quote flow (neither 1/2 Hard nor Stress Relieved). 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, Gold 18K-1/2 Hard or Gold 18K Stress Relieved?
Gold 18K Stress Relieved, by a small margin. Both rate very good for machinability — 75/100 against 70/100 for Gold 18K-1/2 Hard.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Gold 18K-1/2 Hard and Gold 18K Stress Relieved 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.