Precious Metal 18K vs 22K
Precious Metal · grade comparison
Precious Metal 18K and 22K are both precious metal grades. 18K is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 75 MPa (10.9 ksi) for 22K, about 3.2 times as much; tensile strength follows at 450 MPa (65.3 ksi) vs 220 MPa (31.9 ksi). 18K is harder — 143 HB against 52 HB for 22K — which matters for wear surfaces and threads. 18K is lighter (15.5 g/cm³ vs 17.8 g/cm³ for 22K) and 22K runs hotter in service (400°C vs 300°C continuous).
18KChoose it when strength drives the design, or when surface hardness matters.
22KChoose it when the part sees heat.
18K vs 22K: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Same in both: Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Polishability
Same in both: Machinability 50 / 100 · Machinability Rating (AISI 1212 = 100 %) 45% · Castability 85 / 100 · Brazeability / Solderability 95 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 18K | 22K |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
18K vs 22K — frequently asked
Is 18K stronger than 22K?
Yes. 18K has a typical yield strength of 240 MPa (34.8 ksi) against 75 MPa (10.9 ksi) for 22K — about 3.2 times as much. Tensile strength is 450 MPa (65.3 ksi) vs 220 MPa (31.9 ksi).
Which is cheaper, 18K or 22K?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose 18K over 22K?
Pick 18K when strength drives the design, or when surface hardness matters. Pick 22K when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18K and 22K 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.