Precious Metal S990-H01
Supply condition
H01 = quarter hard
Light cold work for sheet that must hold shape during stamping yet still bend without cracking.
Values for the H01 condition
Other S990 tempers and conditions
S990 is listed in 5 conditions; see the grade overview at S990.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Investment-cast jewelry, teaware bodies and figurines before finishing; coarse grain, lowest strength. | 45 | 140 | 25 | 28 HB | 95 % IACS |
ODefault Annealed | Standard supply condition for sheet, wire and tube that will be hammered, drawn, chased or filigree-worked. | 50 | 150 | 45 | 30 HB | 97 % IACS |
H01This page Quarter hard | Light cold work for sheet that must hold shape during stamping yet still bend without cracking. | 150 | 200 | 20 | 52 HB | 96 % IACS |
Half hard | Half-hard strip and wire for bangle stock, chain links and settings needing spring-back resistance. | 200 | 240 | 10 | 66 HB | 95 % IACS |
Full hard | Hard-drawn wire and rolled strip where maximum stiffness and scratch resistance matter (clasps, pins, chain). | 250 | 290 | 4 | 82 HB | 94 % IACS |
What is S990-H01?
S990-H01 is S990 supplied in the H01 condition — light cold work for sheet that must hold shape during stamping yet still bend without cracking. S990-H01 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 68% of precious metal grades. Elongation at break is 20% and the elastic modulus is 78 GPa (11.3 Msi). S990-H01 has a density of 10.48 g/cm³ (0.379 lb/in³), heavier than 54% of precious metal grades. It melts at 940°C (1,724 °F). O is the default condition FabDigit quotes; H01 is available on request or by drawing note.
Advantages
- Conducts heat well — 400 W/m·K (231.1 BTU/hr·ft·°F), better than 97% of precious metal grades
- High electrical conductivity — 96 % IACS, better than 97% of precious metal grades
- Easy to machine — 58/100, better than 95% of precious metal grades
- Polishes to a fine finish — 96/100, better than 94% of precious metal grades
Limitations
- Low stiffness — 78 GPa (11.3 Msi), worse than 90% of precious metal grades
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
- Limited ductility — 20%, worse than 77% of precious metal grades
S990-H01 properties
Typical room-temperature values for S990-H01; 18 are specific to this condition. Other listed values are S990 reference data and may not represent this condition. Bars are the position among precious metal grades.
Physical3
S990-H01 has a density of 10.48 g/cm³ (0.379 lb/in³), heavier than 54% of precious metal grades. It melts at 940°C (1,724 °F).
Mechanical12
S990-H01 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 68% of precious metal grades. Elongation at break is 20% and the elastic modulus is 78 GPa (11.3 Msi).
Thermal6
S990-H01 is rated for continuous service to 200°C (392 °F). It conducts heat at 400 W/m·K (231.1 BTU/hr·ft·°F), better than 97% of precious metal grades. Thermal expansion is 19.6 µm/m·K (10.9 µin/in·°F).
Electrical3
S990-H01 conducts electricity at 96 % IACS, better than 97% of precious metal grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of precious metal grades.
Sustainability4
Producing a kilogram of S990-H01 takes about 1,500 MJ of energy and emits 110 kg of CO₂ — more than 51% of precious metal grades. Typical recycled content is 30%.
Manufacturability8
S990-H01's machinability is good (58/100, better than 95% of precious metal grades); weldability good (55/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S990-H01
Is S990 easy to machine?
Very soft and gummy — use polished, high-rake carbide or HSS tools, high speed, light feed and generous lubricant to avoid smearing; collect all swarf for refining.
Can S990 be welded?
Best joined with laser/PUK spot welding or silver brazing alloys (Ag-Cu-Zn, 650–800 °C); its huge thermal conductivity demands high-power, short-duration heat input.
Can S990 be formed, bent or molded?
Outstanding cold formability — deep draws, raises and forges with 50–70 % reduction between anneals; anneal at 550–650 °C and quench/pickle to remove fire stain, and de-gas melts before investment casting.
What surface finishes work on S990?
Polishes to a mirror with tripoli/rouge; protect with rhodium plating, anti-tarnish lacquer or sulfur-absorbing storage since H₂S blackening is the main service issue.
S990 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 |
|---|---|---|
| Cuusual hardening/deoxidizing addition making up the remainder | ≤ 1 | 0.8 |
| Znoptional, used by some mills as deoxidizer in place of part of the Cu | ≤ 0.3 | 0.1 |
| Geoptional anti-tarnish micro-addition in some proprietary 990 alloys | ≤ 0.3 | — |
| Cdrestricted by GB 28480 jewelry harmful-element limits | ≤ 0.01 | — |
| Pbimpurity limit, refinery practice per ASTM B413 analogue | ≤ 0.02 | — |
| AgGB/T 11887 minimum fineness 990; hallmark S990 | ≥ 99 (balance) | — |
S990-H01 — frequently asked
What is S990-H01 used for?
S990-H01 is typically used for jewelry, ornamental silverware and gift items. In short: highest formability in family; near-pure jewelry fineness; softer than sterling.
What is the yield strength of S990-H01?
S990-H01 has a typical yield strength of 150 MPa (21.8 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 68% of precious metal grades. Strength varies by condition: see the 5 listed tempers.
Is S990-H01 easy to machine?
Reasonably — machinability is rated good (58/100, better than 95% of precious metal grades). Very soft and gummy — use polished, high-rake carbide or HSS tools, high speed, light feed and generous lubricant to avoid smearing; collect all swarf for refining.
Can S990-H01 be welded?
Yes — weldability is rated good (55/100). Best joined with laser/PUK spot welding or silver brazing alloys (Ag-Cu-Zn, 650–800 °C); its huge thermal conductivity demands high-power, short-duration heat input.
What surface finishes work on S990-H01?
Polishes to a mirror with tripoli/rouge; protect with rhodium plating, anti-tarnish lacquer or sulfur-absorbing storage since H₂S blackening is the main service issue.
Can S990-H01 be formed, bent or molded?
Outstanding cold formability — deep draws, raises and forges with 50–70 % reduction between anneals; anneal at 550–650 °C and quench/pickle to remove fire stain, and de-gas melts before investment casting.
What is the maximum service temperature of S990-H01?
S990-H01 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 S990-O and S990-H04?
O is the default condition — standard supply condition for sheet, wire and tube that will be hammered, drawn, chased or filigree-worked. H04: hard-drawn wire and rolled strip where maximum stiffness and scratch resistance matter (clasps, pins, chain). Yield strength is 50 MPa in O versus 250 MPa in H04.
Sources
- ASTM B413 Standard Specification for Refined Silver — ASTM International (2019)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Silver and Silver Alloys) — ASM International (1990)
- ASM Specialty Handbook / Handbook Vol.13B — Corrosion of Silver and Silver Alloys — ASM International (2005)
- CRC Handbook of Chemistry and Physics — thermophysical data for silver — CRC Press (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.