Precious Metal Silver 925-PH (Pre-hardened)
Heat-treated state
also Sterling Silver, STG
Choose when a formed or cast sterling part must be hardened after shaping (spring clips, hinge pins, cutlery handles).
Values for the PH condition
Other Silver 925 tempers and conditions
Silver 925 is listed in 5 conditions; see the grade overview at Silver 925.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Default stock condition for sheet, wire and tube that will be formed, raised, bent or drawn. | 75 | 280 | 40 | 58 HB | 85 % IACS |
As fabricated | Condition of investment-cast jewellery and hollowware straight from the flask, before work hardening or age hardening. | 95 | 230 | 18 | 62 HB | 82 % IACS |
Half hard | Pick for wire, findings and bezels that must hold shape yet still take a moderate bend. | 260 | 380 | 12 | 95 HB | 83 % IACS |
hard / spring temper (≥50 % reduction) | Use for springs, clasps, pin stems and wear-facing parts where maximum strength and stiffness retention matter. | 375 | 450 | 4 | 118 HB | 82 % IACS |
PHThis page Pre-hardened | Choose when a formed or cast sterling part must be hardened after shaping (spring clips, hinge pins, cutlery handles). | 400 | 470 | 6 | 132 HB | 86 % IACS |
What is Silver 925-PH?
Silver 925-PH is Silver 925 heat treated to PH — choose when a formed or cast sterling part must be hardened after shaping (spring clips, hinge pins, cutlery handles). Silver 925-PH has a yield strength of 400 MPa (58 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 96% of precious metal grades. Elongation at break is 6% and the elastic modulus is 77 GPa (11.2 Msi). Silver 925-PH has a density of 10.36 g/cm³ (0.374 lb/in³), heavier than 50% of precious metal grades. It melts at 779°C (1,434 °F). O is the default condition FabDigit quotes; PH is available on request or by drawing note.
Advantages
- Easy to machine — 75/100, better than 101% of precious metal grades
- High strength — 400 MPa (58 ksi), better than 96% of precious metal grades
- Conducts heat well — 365 W/m·K (210.9 BTU/hr·ft·°F), better than 95% of precious metal grades
- High electrical conductivity — 86 % IACS, better than 90% of precious metal grades
- Polishes to a fine finish — 95/100, better than 86% of precious metal grades
Limitations
- Limited formability — 30/100, worse than 94% of precious metal grades
- Low stiffness — 77 GPa (11.2 Msi), worse than 93% of precious metal grades
- Limited ductility — 6%, worse than 93% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
Silver 925-PH properties
Typical room-temperature values for Silver 925-PH; 19 are specific to this condition. Other listed values are Silver 925 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
Silver 925-PH has a density of 10.36 g/cm³ (0.374 lb/in³), heavier than 50% of precious metal grades. It melts at 779°C (1,434 °F).
Mechanical12
Silver 925-PH has a yield strength of 400 MPa (58 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 96% of precious metal grades. Elongation at break is 6% and the elastic modulus is 77 GPa (11.2 Msi).
Thermal6
Silver 925-PH is rated for continuous service to 200°C (392 °F). It conducts heat at 365 W/m·K (210.9 BTU/hr·ft·°F), better than 95% of precious metal grades. Thermal expansion is 18.9 µm/m·K (10.5 µin/in·°F).
Electrical3
Silver 925-PH conducts electricity at 86 % IACS, better than 90% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (75/100), worse than 61% of precious metal grades.
Sustainability4
Producing a kilogram of Silver 925-PH takes about 1,500 MJ of energy and emits 110 kg of CO₂ — more than 51% of precious metal grades. Typical recycled content is 35%.
Manufacturability8
Silver 925-PH's machinability is very good (75/100, better than 101% of precious metal grades); weldability fair (45/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Silver 925-PH
Is Silver 925 easy to machine?
Very soft and gummy in the annealed state — use sharp polished high-rake carbide or HSS, high speed, light feed, and prefer half-hard or age-hardened stock for threads and turned parts; collect all swarf as refinable scrap.
Can Silver 925 be welded?
Laser and micro-TIG welding are routine with matching sterling filler; high thermal conductivity makes resistance welding difficult, and torch work needs a reducing flame plus boric-acid/flux protection against firescale.
Can Silver 925 be formed, bent or molded?
Excellent cold formability when annealed (raising, spinning, stamping, drawing); interanneal at 600–650 °C with a rapid quench after roughly 50–60 % reduction to avoid edge cracking, and investment casts well at 950–1000 °C mould temperature.
What surface finishes work on Silver 925?
Polishes to a mirror finish easily; typical finishes are bright polish, satin, chemical oxidising (liver of sulfur) or rhodium/fine-silver plating for tarnish resistance — anodizing is not applicable.
Silver 925 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 |
|---|---|---|
| Ag925 fineness minimum per ISO 9202 / GB/T 11887 hallmarking | 92.5 – 93.5 | 92.5 |
| Cubalance; may be partly replaced by Zn/Si/Ge/Sn in de-oxidised or tarnish-resistant sterling variants | ≥ 6.5 (balance) | — |
Silver 925-PH — frequently asked
What is Silver 925-PH used for?
Silver 925-PH is typically used for jewelry, tableware and coin minting. In short: sterling silver jewelry sheet.
What is the yield strength of Silver 925-PH?
Silver 925-PH has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 96% of precious metal grades. Strength varies by condition: see the 5 listed tempers.
Is Silver 925-PH easy to machine?
Yes — machinability is rated very good (75/100, better than 101% of precious metal grades). Very soft and gummy in the annealed state — use sharp polished high-rake carbide or HSS, high speed, light feed, and prefer half-hard or age-hardened stock for threads and turned parts; collect all swarf as refinable scrap.
Can Silver 925-PH be welded?
With care — weldability is rated fair (45/100). Laser and micro-TIG welding are routine with matching sterling filler; high thermal conductivity makes resistance welding difficult, and torch work needs a reducing flame plus boric-acid/flux protection against firescale.
What surface finishes work on Silver 925-PH?
Polishes to a mirror finish easily; typical finishes are bright polish, satin, chemical oxidising (liver of sulfur) or rhodium/fine-silver plating for tarnish resistance — anodizing is not applicable.
Can Silver 925-PH be formed, bent or molded?
Excellent cold formability when annealed (raising, spinning, stamping, drawing); interanneal at 600–650 °C with a rapid quench after roughly 50–60 % reduction to avoid edge cracking, and investment casts well at 950–1000 °C mould temperature.
What is the maximum service temperature of Silver 925-PH?
Silver 925-PH 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 Silver 925-O and Silver 925-PH?
O is the default condition — default stock condition for sheet, wire and tube that will be formed, raised, bent or drawn. PH: choose when a formed or cast sterling part must be hardened after shaping (spring clips, hinge pins, cutlery handles). Yield strength is 75 MPa in O versus 400 MPa in PH.
Sources
- ISO 9202 Jewellery — Fineness of precious metal alloys — ISO (2019)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Precious Metals) — ASM International (1990)
- ASM Alloy Phase Diagrams — Ag-Cu system — ASM International (1992)
- Sterling silver sheet & wire technical data — Hoover & Strong / Rio Grande (2024)
- CES EduPack materials data — silver alloys (eco properties) — Granta/Ansys (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.