Solder & Low-Melting Alloy SAC0307
JIS Sn-0.3Ag-0.7Cu
SAC0307 is a low-silver lead-free tin-silver-copper solder (Sn-0.3Ag-0.7Cu) used where the silver cost of SAC305 is a concern but RoHS compliance is still required.
Reference datasheet — SAC0307 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.
What is SAC0307?
SAC0307 is a low-silver lead-free tin-silver-copper solder (Sn-0.3Ag-0.7Cu) used where the silver cost of SAC305 is a concern but RoHS compliance is still required. Engineers specify it for wave, selective and reflow assembly, and it is stocked as bar, wire, solder paste, balls and stamped preforms. The alloy is soft and ductile — 32 MPa tensile, 25 MPa yield, 40 % elongation, 13 HB — so joints are electrical and thermal connections rather than structural members. Wave pots typically run at 255–275 °C and reflow peaks at 235–250 °C; SAC305 is the nearest alternative when joint reliability outweighs silver cost. SAC0307 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 217°C (423 °F). SAC0307 has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 32 MPa (4.64 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 40% and the elastic modulus is 47 GPa (6.82 Msi).
What is SAC0307 used for?
- consumer electronics wave soldering
- cost-sensitive PCB assembly
- through-hole component soldering
Advantages
- Conducts heat well — 60 W/m·K (34.7 BTU/hr·ft·°F), better than 89% of solder & low-melting alloy grades
- High electrical conductivity — 13 % IACS, better than 87% of solder & low-melting alloy grades
- Stiff — 47 GPa (6.82 Msi), better than 77% of solder & low-melting alloy grades
Limitations
- High embodied carbon — 18 kg CO₂/kg, worse than 76% of solder & low-melting alloy grades
SAC0307 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
SAC0307 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 217°C (423 °F).
Mechanical11
SAC0307 has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 32 MPa (4.64 ksi) — weaker than 61% of solder & low-melting alloy grades. Elongation at break is 40% and the elastic modulus is 47 GPa (6.82 Msi).
Thermal6
SAC0307 is rated for continuous service to 100°C (212 °F). It conducts heat at 60 W/m·K (34.7 BTU/hr·ft·°F), better than 89% of solder & low-melting alloy grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
SAC0307 conducts electricity at 13 % IACS, better than 87% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of SAC0307 takes about 330 MJ of energy and emits 18 kg of CO₂ — more than 86% of solder & low-melting alloy grades. Typical recycled content is 30%.
Manufacturability7
SAC0307's machinability is poor (30/100, worse than 60% of solder & low-melting alloy grades); weldability poor (20/100); 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 solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. SAC0307 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SAC0307
Is SAC0307 easy to machine?
Very soft and gummy — machining is rarely done; use sharp positive-rake tools, high speed and no coolant-induced smearing if trimming preforms.
Can SAC0307 be welded?
Not fusion welded; the alloy itself is the filler — pot temperature typically 255–275 °C for wave, 235–250 °C peak for reflow.
Can SAC0307 be formed, bent or molded?
Extrudes and rolls easily into wire, ribbon and stamped preforms at room temperature; atomises well into Type 3–5 paste powder.
SAC0307 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 |
|---|---|---|
| Ag | 0.2 – 0.4 | 0.3 |
| Cu | 0.6 – 0.8 | 0.7 |
| PbRoHS/J-STD-006 impurity limit; <0.1 % for lead-free claim | ≤ 0.07 | |
| Sbimpurity | ≤ 0.1 | |
| Biimpurity | ≤ 0.1 | |
| Feimpurity | ≤ 0.02 | |
| Znimpurity | ≤ 0 | |
| Alimpurity | ≤ 0 | |
| Asimpurity | ≤ 0.03 | |
| Cdimpurity | ≤ 0 | |
| Sn≈99.0 % | balance |
What surface finishes work on SAC0307?
Joints are left as-soldered; clean no-clean or rosin residues where conformal coating follows, and avoid sulphur-bearing atmospheres to prevent creep corrosion.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy SAC0307 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- JIS
- Sn-0.3Ag-0.7Cu
How much does SAC0307 cost?
SAC0307 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SAC0307 — frequently asked
What is SAC0307 used for?
SAC0307 is typically used for consumer electronics wave soldering, cost-sensitive PCB assembly and through-hole component soldering. In short: low-silver SAC alloy; lower cost than SAC305; lead-free wave and reflow.
What is the yield strength of SAC0307?
SAC0307 has a typical yield strength of 25 MPa (3.63 ksi) and a tensile strength of 32 MPa (4.64 ksi) — weaker than 61% of solder & low-melting alloy grades.
Is SAC0307 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 60% of solder & low-melting alloy grades). Very soft and gummy — machining is rarely done; use sharp positive-rake tools, high speed and no coolant-induced smearing if trimming preforms.
Can SAC0307 be welded?
Not readily — weldability is rated poor (20/100). Not fusion welded; the alloy itself is the filler — pot temperature typically 255–275 °C for wave, 235–250 °C peak for reflow.
What surface finishes work on SAC0307?
Joints are left as-soldered; clean no-clean or rosin residues where conformal coating follows, and avoid sulphur-bearing atmospheres to prevent creep corrosion.
Can SAC0307 be formed, bent or molded?
Extrudes and rolls easily into wire, ribbon and stamped preforms at room temperature; atomises well into Type 3–5 paste powder.
What is the maximum service temperature of SAC0307?
SAC0307 is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does SAC0307 cost?
SAC0307 is a high-cost solder & low-melting alloy ($$$$), 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
- J-STD-006C Requirements for Electronic Grade Solder Alloys — IPC/JEDEC (2013)
- GB/T 20422 — SAC (China) (2018)
- NIST Database for Solder Properties with Emphasis on New Lead-free Solders — NIST/Colorado School of Mines (2002)
- Low-silver SAC (SACX/SAC0307) solder alloy datasheets — Alpha Assembly / Nihon Superior / Indium Corporation (2023)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering — ASM International (1993)
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.