Precious Metal Gold 18K Stress Relieved
Heat-treated state
Use after cold forming or machining to cut residual stress and stress-corrosion risk while keeping most of the work-hardened strength.
Values for the Stress Relieved condition
Other Gold 18K tempers and conditions
Gold 18K is listed in 6 conditions; see the grade overview at Gold 18K.
- O
- As Cast
- 1/2 Hard
- Stress Relieved
- Cold Worked
- Age Hardened
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Default stocked condition for sheet, wire and tube that will be bent, stamped, drawn or stone-set. | 200 | 450 | 40 | 140 HB | — |
investment / centrifugal cast, no post heat treatment | Standard state of cast jewellery bodies and hollowware; coarse dendritic grain gives lower ductility than annealed wrought stock. | 230 | 420 | 22 | 145 HB | 185 W/m·K |
Half hard | Compromise temper for sheet and wire that must still take moderate bending but resist deformation in service. | 500 | 640 | 10 | 14 HRC | 15 % IACS |
Stress RelievedThis page cold worked + low-temperature relief (250–300 °C) | Use after cold forming or machining to cut residual stress and stress-corrosion risk while keeping most of the work-hardened strength. | 580 | 700 | 9 | 17 HRC | 15 % IACS |
hard (≈50–70 % reduction) | Choose for springy clasps, pins, wire and thin sections needing maximum strength and dent resistance. | 660 | 780 | 4 | 220 HB | 15 % IACS |
order-hardened (quench from ~650 °C, age 250–300 °C) | Applies to Cu-rich 18K yellow/rose (AuCu ordering) and to Ni/Pd 18K white: raises hardness of finished, non-deformable parts such as watch cases and prong settings. | 680 | 800 | 6 | 22 HRC | 19 % IACS |
What is Gold 18K Stress Relieved?
Gold 18K Stress Relieved is Gold 18K heat treated to Stress Relieved — use after cold forming or machining to cut residual stress and stress-corrosion risk while keeping most of the work-hardened strength. Gold 18K Stress Relieved has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 97% of precious metal grades. Elongation at break is 9% and the elastic modulus is 79 GPa (11.5 Msi). Gold 18K Stress Relieved has a density of 15.5 g/cm³ (0.56 lb/in³), heavier than 77% of precious metal grades. It melts at 895°C (1,643 °F). O is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.
Advantages
- Easy to machine — 75/100, better than 101% of precious metal grades
- Polishes to a fine finish — 98/100, better than 98% of precious metal grades
- High strength — 580 MPa (84.1 ksi), better than 97% of precious metal grades
- Readily welded — 75/100, better than 78% of precious metal grades
Limitations
- Limited formability — 35/100, worse than 92% of precious metal grades
- Limited ductility — 9%, worse than 91% of precious metal grades
- Low stiffness — 79 GPa (11.5 Msi), worse than 86% of precious metal grades
- Heavy — 15.5 g/cm³ (0.56 lb/in³), worse than 77% of precious metal grades
Gold 18K Stress Relieved properties
Typical room-temperature values for Gold 18K Stress Relieved; 21 are specific to this condition. Other listed values are Gold 18K reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Gold 18K Stress Relieved has a density of 15.5 g/cm³ (0.56 lb/in³), heavier than 77% of precious metal grades. It melts at 895°C (1,643 °F).
Mechanical12
Gold 18K Stress Relieved has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 97% of precious metal grades. Elongation at break is 9% and the elastic modulus is 79 GPa (11.5 Msi).
Thermal6
Gold 18K Stress Relieved is rated for continuous service to 250°C (482 °F). It conducts heat at 180 W/m·K (104 BTU/hr·ft·°F), better than 67% of precious metal grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
Gold 18K Stress Relieved conducts electricity at 15 % IACS, worse than 65% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (91/100), better than 70% of precious metal grades.
Sustainability4
Producing a kilogram of Gold 18K Stress Relieved takes about 180,000 MJ of energy and emits 11,000 kg of CO₂ — more than 77% of precious metal grades. Typical recycled content is 30%.
Manufacturability8
Gold 18K Stress Relieved's machinability is very good (75/100, better than 101% of precious metal grades); weldability very good (75/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Gold 18K Stress Relieved
Is Gold 18K easy to machine?
Turns and engraves beautifully with sharp PCD/carbide tools, high speed, low feed and light cuts; annealed material is gummy, so half-hard stock and swarf recovery for refining are standard practice.
Can Gold 18K be welded?
Excellent with pulsed Nd:YAG/fibre laser and PUK micro-TIG using matching 18K filler; oxyacetylene brazing with graded gold solders is routine, but avoid overheating Zn-bearing casting alloys.
Can Gold 18K be formed, bent or molded?
In the annealed temper it rolls, draws, spins and stamps readily with interstage anneals at 650–700 °C; investment casting at 950–1050 °C mould temperature is the dominant route, plus SLM for complex parts.
What surface finishes work on Gold 18K?
Polishes to a mirror with tripoli/rouge and can be electroformed, rhodium- or Pd-plated (whites) and PVD coated; no anodising — ultrasonic and steam cleaning are the usual final steps.
Gold 18K chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Au750 ‰ legal fineness minimum; refiners aim 75.2–75.5 % to stay above assay tolerance | 75 – 75.8 | 75 |
| Agyellow 18K; near zero in Ni/Pd whites | 0 – 16 | 12.5 |
| Zndeoxidiser / colour and flow modifier in casting alloys | 0 – 4 | 0.5 |
| Ni18K white (Au-Ni-Cu-Zn) only; restricted by EU nickel-release rules | 0 – 13 | 0 |
| Pdnickel-free 18K white (Au-Pd-Ag-Cu) | 0 – 15 | 0 |
| Co+Ir+Ru+Sigrain refiners / deoxidisers in casting and 3D-printing powders | 0 – 0.3 | 0.05 |
| Cubalance of the 250 ‰ base metal; up to ~25 % in 18K red/rose | ≥ 0 (balance) |
Gold 18K Stress Relieved — frequently asked
What is Gold 18K Stress Relieved used for?
Gold 18K Stress Relieved is typically used for fine jewelry rings and bracelets, watch cases and bezels, dental crowns and inlays, decorative electronics trim, engraved medallions and awards and clasps, cufflinks and findings. In short: premium 18K jewelry gold.
What is the yield strength of Gold 18K Stress Relieved?
Gold 18K Stress Relieved has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 97% of precious metal grades. Strength varies by condition: see the 6 listed tempers.
Is Gold 18K Stress Relieved easy to machine?
Yes — machinability is rated very good (75/100, better than 101% of precious metal grades). Turns and engraves beautifully with sharp PCD/carbide tools, high speed, low feed and light cuts; annealed material is gummy, so half-hard stock and swarf recovery for refining are standard practice.
Can Gold 18K Stress Relieved be welded?
Yes — weldability is rated very good (75/100). Excellent with pulsed Nd:YAG/fibre laser and PUK micro-TIG using matching 18K filler; oxyacetylene brazing with graded gold solders is routine, but avoid overheating Zn-bearing casting alloys.
What surface finishes work on Gold 18K Stress Relieved?
Polishes to a mirror with tripoli/rouge and can be electroformed, rhodium- or Pd-plated (whites) and PVD coated; no anodising — ultrasonic and steam cleaning are the usual final steps.
Can Gold 18K Stress Relieved be formed, bent or molded?
In the annealed temper it rolls, draws, spins and stamps readily with interstage anneals at 650–700 °C; investment casting at 950–1050 °C mould temperature is the dominant route, plus SLM for complex parts.
What is the maximum service temperature of Gold 18K Stress Relieved?
Gold 18K Stress Relieved is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- The Metallurgy of Carat Gold Alloys / Gold Bulletin property compilations — World Gold Council / Springer (2004)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys (Precious Metals) — ASM International (1990)
- ISO 9202 Jewellery — Fineness of precious metal alloys — ISO (2019)
- 18K gold casting alloys and SLM powder data — Cooksongold / Legor Group / Hoover & Strong (2023)
- CES EduPack precious-metal eco-property records (scaled to 750 ‰) — Ansys Granta (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.