Precious Metal Dental Gold Type IV SOFT
Hardness band
ASTM ADA Spec No.5 Type IV · ISO 1562 Type 4
SOFT = softened
Choose when clasps or margins must be adjusted, burnished or soldered before final hardening.
Values for the SOFT condition
Other Dental Gold Type IV tempers and conditions
Dental Gold Type IV is listed in 3 conditions; see the grade overview at Dental Gold Type IV.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SOFTThis page Softened | Choose when clasps or margins must be adjusted, burnished or soldered before final hardening. | 360 | 490 | 25 | 172 HB | 13 % IACS |
Spheroidize annealed | Condition of a casting devested without extra heat treatment; partially ordered, intermediate strength and ductility. | 420 | 560 | 15 | 195 HB | 12 % IACS |
HardDefault Age/order hardened | Standard delivery condition for partial denture frameworks and thin high-stress castings needing maximum proof stress and hardness. | 570 | 750 | 6 | 22 HRC | 15 % IACS |
What is Dental Gold Type IV SOFT?
Dental Gold Type IV SOFT is Dental Gold Type IV heat treated to SOFT — choose when clasps or margins must be adjusted, burnished or soldered before final hardening. Dental Gold Type IV SOFT has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 95% of precious metal grades. Elongation at break is 25% and the elastic modulus is 93 GPa (13.5 Msi). Dental Gold Type IV SOFT has a density of 15.5 g/cm³ (0.56 lb/in³), heavier than 77% of precious metal grades. It melts at 880°C (1,616 °F). Hard is the default condition FabDigit quotes; SOFT is available on request or by drawing note.
Advantages
- Easy to machine — 60/100, better than 97% of precious metal grades
- High strength — 360 MPa (52.2 ksi), better than 95% of precious metal grades
- Polishes to a fine finish — 95/100, better than 86% of precious metal grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Limited formability — 70/100, worse than 78% of precious metal grades
- Heavy — 15.5 g/cm³ (0.56 lb/in³), worse than 77% of precious metal grades
Dental Gold Type IV SOFT properties
Typical room-temperature values for Dental Gold Type IV SOFT; 22 are specific to this condition. Other listed values are Dental Gold Type IV reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Dental Gold Type IV SOFT has a density of 15.5 g/cm³ (0.56 lb/in³), heavier than 77% of precious metal grades. It melts at 880°C (1,616 °F).
Mechanical16
Dental Gold Type IV SOFT has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 95% of precious metal grades. Elongation at break is 25% and the elastic modulus is 93 GPa (13.5 Msi).
Thermal6
Dental Gold Type IV SOFT is rated for continuous service to 200°C (392 °F). It conducts heat at 57 W/m·K (32.9 BTU/hr·ft·°F), worse than 74% of precious metal grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
Dental Gold Type IV SOFT conducts electricity at 13 % IACS, worse than 72% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 73% of precious metal grades.
Sustainability3
Producing a kilogram of Dental Gold Type IV SOFT takes about 140,000 MJ of energy and emits 8,500 kg of CO₂ — more than 71% of precious metal grades. Typical recycled content is 60%.
Manufacturability8
Dental Gold Type IV SOFT's machinability is good (60/100, better than 97% of precious metal grades); weldability very good (72/100); 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 IV SOFT
Is Dental Gold Type IV easy to machine?
Cuts easily but smears — use sharp carbide/HSS tools, light feeds and collect all swarf for refining.
Can Dental Gold Type IV be welded?
Laser and pulse-arc welded routinely in the softened state; gold solders (lower-melting) used for joining framework sections before hardening.
Can Dental Gold Type IV be formed, bent or molded?
Primarily lost-wax investment cast at ~1000 °C melt with gypsum-bonded investment; clasps can be bent only in the softened condition.
What surface finishes work on Dental Gold Type IV?
Excellent polishability to a mirror finish with rouge; not anodizable, electroplating or heat-tint colouring only if a different shade is required.
Dental Gold Type IV 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 |
|---|---|---|
| Auhigh-noble class; Au+Pt-group ≥ 75 % for ADA Type IV | 60 – 71 | 65 |
| Ag | 4 – 15 | 10 |
| Pdraises melting range and tarnish resistance | 0 – 5 | 3 |
| Ptgrain refinement and strength | 0 – 4 | 3 |
| Zndeoxidiser, improves casting fluidity | 0 – 2 | 1 |
| Irgrain refiner (trace) | 0 – 0.01 | 0.01 |
| Cuprovides AuCu ordering / age hardening | ≥ 9 (balance) | — |
Dental Gold Type IV SOFT — frequently asked
What is Dental Gold Type IV SOFT used for?
Dental Gold Type IV SOFT is typically used for removable partial denture frameworks, clasps and thin high-stress castings. In short: hardest ADA dental gold; highest elastic limit; framework and clasp alloy.
What is the yield strength of Dental Gold Type IV SOFT?
Dental Gold Type IV SOFT has a typical yield strength of 360 MPa (52.2 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 95% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is Dental Gold Type IV SOFT easy to machine?
Reasonably — machinability is rated good (60/100, better than 97% of precious metal grades). Cuts easily but smears — use sharp carbide/HSS tools, light feeds and collect all swarf for refining.
Can Dental Gold Type IV SOFT be welded?
Yes — weldability is rated very good (72/100). Laser and pulse-arc welded routinely in the softened state; gold solders (lower-melting) used for joining framework sections before hardening.
What surface finishes work on Dental Gold Type IV SOFT?
Excellent polishability to a mirror finish with rouge; not anodizable, electroplating or heat-tint colouring only if a different shade is required.
Can Dental Gold Type IV SOFT be formed, bent or molded?
Primarily lost-wax investment cast at ~1000 °C melt with gypsum-bonded investment; clasps can be bent only in the softened condition.
What is the maximum service temperature of Dental Gold Type IV SOFT?
Dental Gold Type IV SOFT is rated for continuous use to about 200°C (392 °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 IV Hard and Dental Gold Type IV SOFT?
Hard is the default condition — standard delivery condition for partial denture frameworks and thin high-stress castings needing maximum proof stress and hardness. SOFT: choose when clasps or margins must be adjusted, burnished or soldered before final hardening. Yield strength is 570 MPa in Hard versus 360 MPa in SOFT.
Sources
- ISO 1562 Dentistry — Casting gold alloys — ISO (2004)
- ANSI/ADA Specification No.5 — Dental Casting Alloys — American Dental Association (2000)
- Phillips' Science of Dental Materials — Elsevier (2012)
- Craig's Restorative Dental Materials — Elsevier (2019)
- ASM Handbook Vol.2 — Properties of Precious Metals — ASM International (1990)
- Dental casting gold alloy datasheets (Type 4 / extra hard) — Ivoclar / Heraeus Kulzer / Jensen Dental (2020)
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.