Precious Metal PSr70
GOST PSr70 (ПСр70)
ПСр70 is a high-silver Ag-Cu-Zn braze filler to GOST 19738, close in silver content and application to AWS BAg-10.
Reference datasheet — PSr70 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
PSr70 tempers and conditions
PSr70 is supplied in 3 conditions, soft to hard.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As cast | Melting-shop feedstock for re-drawing, atomizing or remelt; not used directly at the joint. | 130 | 280 | 15 | 75 HB | 37 % IACS |
As built (as printed) | Property set describing the solidified joint after brazing — used for joint-strength design checks. | 150 | 300 | 18 | 80 HB | 38 % IACS |
Hard-drawn wire | Choose when stiff straight lengths or automatic ring-feeding requires spring-back and dimensional stiffness. | 430 | 520 | 5 | 142 HB | 38 % IACS |
Supply forms, finishes and certifications
Ways PSr70 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ANN-WIREDefault | Annealed wire / rod | Supply form |
POWDER-PASTE | Atomized powder / brazing paste | Supply form |
STRIP | Rolled strip / foil preform stock | Supply form |
What is PSr70?
ПСр70 is a high-silver Ag-Cu-Zn braze filler to GOST 19738, close in silver content and application to AWS BAg-10. The high silver content gives a narrow melting range, fast capillary flow into tight joints and good ductility — 350 MPa tensile, 170 MPa yield, 28 % elongation and 85 HB — and it is supplied as annealed or hard-drawn wire, strip, powder/paste and cast stock. Silver cost per joint is the main limit, and the zinc content makes it unsuitable for high-vacuum brazing. Drop to ПСр45 where silver price dominates and gap fit is less critical. PSr70 has a density of 9.85 g/cm³ (0.356 lb/in³), lighter than 73% of precious metal grades. It melts at 730°C (1,346 °F). PSr70 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 64% of precious metal grades. Elongation at break is 28% and the elastic modulus is 85 GPa (12.3 Msi).
What is PSr70 used for?
- stainless steel brazing
- instrument and electrical brazing
- precision assembly brazing
Advantages
- Easy to machine — 55/100, better than 86% of precious metal grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 89% of precious metal grades
PSr70 properties
Typical room-temperature values; bars are the position among precious metal grades.
Physical3
PSr70 has a density of 9.85 g/cm³ (0.356 lb/in³), lighter than 73% of precious metal grades. It melts at 730°C (1,346 °F).
Mechanical10
PSr70 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 64% of precious metal grades. Elongation at break is 28% and the elastic modulus is 85 GPa (12.3 Msi).
Thermal6
PSr70 is rated for continuous service to 200°C (392 °F). It conducts heat at 160 W/m·K (92.4 BTU/hr·ft·°F), better than 66% of precious metal grades. Thermal expansion is 19 µm/m·K (10.6 µin/in·°F).
Electrical3
PSr70 conducts electricity at 40 % IACS, better than 68% 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 PSr70 takes about 1,100 MJ of energy and emits 95 kg of CO₂ — less than 71% of precious metal grades. Typical recycled content is 50%.
Manufacturability6
PSr70's machinability is good (55/100, better than 86% of precious metal grades); weldability poor (30/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the precious metal family
Yield strength against density for every precious metal grade FabDigit runs. PSr70 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PSr70
Is PSr70 easy to machine?
Rarely machined; the soft, gummy Ag-Cu matrix smears — use sharp, high-rake tools and light cuts if trimming preforms.
Can PSr70 be welded?
Not a weldable structural alloy; it is the filler itself — torch, induction, furnace or resistance brazing at about 760–830 °C with silver-braze flux or in dry hydrogen/vacuum (mind Zn volatilization in vacuum).
Can PSr70 be formed, bent or molded?
Excellent cold formability in the annealed state — draws to fine wire, rolls to foil and stamps into rings/shims; interanneal after ~50 % reduction.
PSr70 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 |
|---|---|---|
| Agsilver content defining the grade | 69.5 – 70.5 | 70 |
| Znmelting-range depressant, improves flow | 3.5 – 4.5 | 4 |
| Pbimpurity limit | ≤ 0.01 | — |
| Feimpurity limit | ≤ 0.05 | — |
| Biimpurity limit | ≤ 0.01 | — |
| Total impuritiesper GOST 19738 purity requirement | ≤ 0.15 | — |
| Cubalance, ~26 % | balance | — |
What surface finishes work on PSr70?
Joint fillets clean up readily by pickling off flux residues and light polishing; the silver-rich surface tarnishes in sulfide atmospheres and can be lacquered or plated if appearance matters.
Equivalent designations
Standards and trade names that resolve to Precious Metal PSr70 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GOST
- ПСр70
How much does PSr70 cost?
PSr70 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PSr70 — frequently asked
What is PSr70 used for?
PSr70 is typically used for stainless steel brazing, instrument and electrical brazing and precision assembly brazing. In short: highest-silver GOST braze; narrow melting range; AWS BAg-10 equivalent.
What is the yield strength of PSr70?
PSr70 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 64% of precious metal grades. Strength varies by condition: see the 3 listed tempers.
Is PSr70 easy to machine?
Reasonably — machinability is rated good (55/100, better than 86% of precious metal grades). Rarely machined; the soft, gummy Ag-Cu matrix smears — use sharp, high-rake tools and light cuts if trimming preforms.
Can PSr70 be welded?
Not readily — weldability is rated poor (30/100). Not a weldable structural alloy; it is the filler itself — torch, induction, furnace or resistance brazing at about 760–830 °C with silver-braze flux or in dry hydrogen/vacuum (mind Zn volatilization in vacuum).
What surface finishes work on PSr70?
Joint fillets clean up readily by pickling off flux residues and light polishing; the silver-rich surface tarnishes in sulfide atmospheres and can be lacquered or plated if appearance matters.
Can PSr70 be formed, bent or molded?
Excellent cold formability in the annealed state — draws to fine wire, rolls to foil and stamps into rings/shims; interanneal after ~50 % reduction.
What is the maximum service temperature of PSr70?
PSr70 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PSr70 cost?
PSr70 is a high-cost precious metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GOST 19738-74 Припои серебряные. Марки — Gosstandart / Rosstandart (1974)
- AWS A5.8/A5.8M Specification for Filler Metals for Brazing and Braze Welding (BAg-10 comparison) — AWS (2019)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (silver brazing filler metals) — ASM International (1993)
- AWS Brazing Handbook, 5th ed. — AWS (2007)
- Ag-Cu-Zn phase and property data compilations — ASM Alloy Phase Diagram Database (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.