Precious Metal Dental Gold Type II Hard
Supply condition
ASTM ADA Spec No.5 Type II · ISO 1562 Type 2
Hard = hardened
Use where a Type II restoration must carry higher occlusal stress or resist wear at contacts; ductility drops.
Values for the Hard condition
Other Dental Gold Type II tempers and conditions
Dental Gold Type II is listed in 3 conditions; see the grade overview at Dental Gold Type II.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Softened | Pick when maximum ductility is needed for margin burnishing, adjustment or soldering. | 185 | 350 | 36 | 90 HB | 14 % IACS |
AS-CASTDefault bench-cooled lost-wax casting | Standard condition of a finished inlay/onlay straight from investment casting and devesting. | 200 | 380 | 32 | 100 HB | 15 % IACS |
HardThis page Hardened | Use where a Type II restoration must carry higher occlusal stress or resist wear at contacts; ductility drops. | 280 | 450 | 18 | 128 HB | 16 % IACS |
What is Dental Gold Type II Hard?
Dental Gold Type II Hard is Dental Gold Type II supplied in the Hard condition — use where a Type II restoration must carry higher occlusal stress or resist wear at contacts; ductility drops. Dental Gold Type II Hard has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 88% of precious metal grades. Elongation at break is 18% and the elastic modulus is 98 GPa (14.2 Msi). Dental Gold Type II Hard has a density of 15.6 g/cm³ (0.564 lb/in³), heavier than 79% of precious metal grades. It melts at 910°C (1,670 °F). AS-CAST is the default condition FabDigit quotes; Hard is available on request or by drawing note.
Advantages
- Easy to machine — 70/100, better than 101% of precious metal grades
- Polishes to a fine finish — 98/100, better than 98% of precious metal grades
- High strength — 280 MPa (40.6 ksi), better than 88% of precious metal grades
- Good corrosion resistance — 95/100, better than 82% of precious metal grades
Limitations
- Limited ductility — 18%, worse than 83% of precious metal grades
- High embodied carbon — 13,000 kg CO₂/kg, worse than 81% of precious metal grades
- Heavy — 15.6 g/cm³ (0.564 lb/in³), worse than 79% of precious metal grades
- Limited formability — 70/100, worse than 78% of precious metal grades
Dental Gold Type II Hard properties
Typical room-temperature values for Dental Gold Type II Hard; 19 are specific to this condition. Other listed values are Dental Gold Type II reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Dental Gold Type II Hard has a density of 15.6 g/cm³ (0.564 lb/in³), heavier than 79% of precious metal grades. It melts at 910°C (1,670 °F).
Mechanical13
Dental Gold Type II Hard has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 88% of precious metal grades. Elongation at break is 18% and the elastic modulus is 98 GPa (14.2 Msi).
Thermal6
Dental Gold Type II Hard is rated for continuous service to 300°C (572 °F). It conducts heat at 105 W/m·K (60.7 BTU/hr·ft·°F), better than 59% of precious metal grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
Dental Gold Type II Hard conducts electricity at 16 % IACS, worse than 60% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (95/100), better than 82% of precious metal grades.
Sustainability4
Producing a kilogram of Dental Gold Type II Hard takes about 190,000 MJ of energy and emits 13,000 kg of CO₂ — more than 81% of precious metal grades. Typical recycled content is 60%.
Manufacturability8
Dental Gold Type II Hard's machinability is very good (70/100, better than 101% of precious metal grades); weldability good (65/100); formability very good (70/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Dental Gold Type II Hard
Is Dental Gold Type II easy to machine?
Very soft and gummy — use sharp carbide or diamond tooling, high speed, light feed and collect all swarf for refining.
Can Dental Gold Type II be welded?
Laser welds cleanly without filler; torch soldering with matched dental gold solders below the solidus is routine.
Can Dental Gold Type II be formed, bent or molded?
Excellent lost-wax investment castability with gypsum-bonded investment; margins are readily burnished and cold worked in the soft condition.
What surface finishes work on Dental Gold Type II?
Polishes to a permanent mirror finish with rouge; no plating, passivation or anodising needed.
Dental Gold Type II 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 |
|---|---|---|
| AuAu + Pt-group ≥ 78 % for ADA Type II | 72 – 80 | 75.5 |
| Ag | 8 – 15 | 12 |
| Pd | 0 – 3 | 1.5 |
| Pt | 0 – 4 | 1 |
| Zndeoxidiser, improves castability | 0 – 2 | 1 |
| Irgrain refiner, optional | 0 – 0.01 | 0.01 |
| Cubalance, controls age-hardening | ≥ 5 (balance) | — |
Dental Gold Type II Hard — frequently asked
What is Dental Gold Type II Hard used for?
Dental Gold Type II Hard is typically used for dental inlays, onlays and moderate-stress restorations. In short: mid-hardness dental gold; near-inert in oral service; castable and burnishable.
What is the yield strength of Dental Gold Type II Hard?
Dental Gold Type II Hard has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 88% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is Dental Gold Type II Hard easy to machine?
Yes — machinability is rated very good (70/100, better than 101% of precious metal grades). Very soft and gummy — use sharp carbide or diamond tooling, high speed, light feed and collect all swarf for refining.
Can Dental Gold Type II Hard be welded?
Yes — weldability is rated good (65/100). Laser welds cleanly without filler; torch soldering with matched dental gold solders below the solidus is routine.
What surface finishes work on Dental Gold Type II Hard?
Polishes to a permanent mirror finish with rouge; no plating, passivation or anodising needed.
Can Dental Gold Type II Hard be formed, bent or molded?
Excellent lost-wax investment castability with gypsum-bonded investment; margins are readily burnished and cold worked in the soft condition.
What is the maximum service temperature of Dental Gold Type II Hard?
Dental Gold Type II Hard is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Dental Gold Type II AS-CAST and Dental Gold Type II Hard?
AS-CAST is the default condition — standard condition of a finished inlay/onlay straight from investment casting and devesting. Hard: use where a Type II restoration must carry higher occlusal stress or resist wear at contacts; ductility drops. Yield strength is 200 MPa in AS-CAST versus 280 MPa in Hard.
Sources
- ISO 1562 Dentistry — Casting gold alloys — ISO (2004)
- ANSI/ADA Specification No. 5 — Dental Casting Alloys — American Dental Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Precious Metals) — ASM International (1990)
- Phillips' Science of Dental Materials — Elsevier (2012)
- Dental casting gold alloy datasheets (Type II, ~75 % Au) — Precious-metal dental alloy producers (2023)
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.