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Precious Metal Gold 18K Cold Worked vs Gold 18K-O

Precious Metal · Gold 18K temper comparison

Gold 18K Cold Worked and Gold 18K-O are two conditions of the same precious metal grade, Gold 18K: Cold Worked versus O (annealed). The chemistry is identical, so every difference below comes from the condition. Gold 18K Cold Worked is the stronger of the two: yield strength 660 MPa (95.7 ksi) against 200 MPa (29 ksi) for Gold 18K-O, about 3.3 times as much; tensile strength follows at 780 MPa (113 ksi) vs 450 MPa (65.3 ksi). In exchange, Gold 18K-O is the more ductile: elongation 40% versus 4% for Gold 18K Cold Worked, and Gold 18K Cold Worked is harder (220 HB vs 140 HB). Gold 18K-O runs hotter in service (400°C vs 200°C continuous). On the shop floor, Gold 18K Cold Worked machines more easily (very good vs good).

Gold 18K Cold WorkedChoose it when strength drives the design, or when the part is machined in volume.

Gold 18K-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

Gold 18K Cold Worked vs Gold 18K-O: properties

Gold 18K Cold WorkedGold 18K-O

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

780 MPa113 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

660 MPa95.7 ksi
200 MPa29 ksi

Elongation at Break

4%
40%

Shear Strength

470 MPa68.2 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
150 MPa21.8 ksi

Hardness, Brinell

220 HB
140 HB

Hardness, Rockwell B

97 HRB
75 HRB

Hardness, Vickers

235 HV
150 HV

Same in both: Elastic (Young's) Modulus 78 GPa11.3 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.

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Same in both: Thermal Conductivity 190 W/m·K110 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 · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

15 % IACS
16 % IACS

Same in both: Electrical Resistivity 1.1×10⁻⁷ Ω·m4.33 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) 0.25 V · Corrosion Resistance 93 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

75 / 100
60 / 100

Formability (cold)

25 / 100
95 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 55% · Weldability 85 / 100 · 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.

50100200500101520Density (g/cm³)Yield strength (MPa) — log scaleGold 18K

Gold 18K Cold Worked vs Gold 18K-O — frequently asked

Is Gold 18K Cold Worked stronger than Gold 18K-O?

Yes. Gold 18K Cold Worked has a typical yield strength of 660 MPa (95.7 ksi) against 200 MPa (29 ksi) for Gold 18K-O — about 3.3 times as much. Tensile strength is 780 MPa (113 ksi) vs 450 MPa (65.3 ksi).

Which condition does FabDigit quote by default, Cold Worked or O?

O is the default Gold 18K 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, Gold 18K Cold Worked or Gold 18K-O?

Gold 18K Cold Worked. Its machinability rates very good (75/100) against good (60/100) for Gold 18K-O.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Gold 18K Cold Worked and Gold 18K-O 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.