Solder & Low-Melting Alloy Pb70Sn30
ASTM B32 Sn30 · GB HLSnPb30-70 · ISO 9453-116
Pb70Sn30 is a lead-rich tin-lead soft solder (ASTM B32 Sn30, HLSnPb30-70) with a 183–255 °C pasty range that stays plastic well above the eutectic.
Reference datasheet — Pb70Sn30 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 Pb70Sn30?
Pb70Sn30 is a lead-rich tin-lead soft solder (ASTM B32 Sn30, HLSnPb30-70) with a 183–255 °C pasty range that stays plastic well above the eutectic. Engineers use it for wiping and seam filling on automotive bodies, radiator seams and cable sheaths; stock forms are cast bar, solid and cored wire, paste and preforms. Strength is low — 38 MPa tensile, 22 MPa yield, 45 % elongation, 12 HB — and service temperature is limited to about 100 °C, so joints must not be loaded structurally. Lead content excludes it from RoHS electronics and potable-water service; Sn60Pb40 is the alternative when wetting and joint strength matter more than working time. Pb70Sn30 has a density of 9.7 g/cm³ (0.35 lb/in³), heavier than 70% of solder & low-melting alloy grades. It melts at 183°C (361 °F). Pb70Sn30 has a yield strength of 22 MPa (3.19 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 25 GPa (3.63 Msi).
What is Pb70Sn30 used for?
- auto body filler solder
- radiator seams
- cable sheath joints
- general low-stress soldering
Advantages
- Ductile — tolerates forming and impact — 45%, better than 84% of solder & low-melting alloy grades
- Good corrosion resistance — 55/100, better than 78% of solder & low-melting alloy grades
Pb70Sn30 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
Pb70Sn30 has a density of 9.7 g/cm³ (0.35 lb/in³), heavier than 70% of solder & low-melting alloy grades. It melts at 183°C (361 °F).
Mechanical9
Pb70Sn30 has a yield strength of 22 MPa (3.19 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of solder & low-melting alloy grades. Elongation at break is 45% and the elastic modulus is 25 GPa (3.63 Msi).
Thermal6
Pb70Sn30 is rated for continuous service to 100°C (212 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 53% of solder & low-melting alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
Pb70Sn30 conducts electricity at 9 % IACS, worse than 54% of solder & low-melting alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), better than 78% of solder & low-melting alloy grades.
Sustainability4
Producing a kilogram of Pb70Sn30 takes about 96 MJ of energy and emits 6.1 kg of CO₂ — less than 70% of solder & low-melting alloy grades. Typical recycled content is 45%.
Manufacturability7
Pb70Sn30's machinability is poor (30/100, worse than 60% of solder & low-melting alloy grades); weldability poor (15/100); formability excellent (90/100).
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. Pb70Sn30 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Pb70Sn30
Is Pb70Sn30 easy to machine?
Practically never machined — extremely soft and gummy; if unavoidable use very sharp high-rake tools, high speed, low feed and paraffin/kerosene lubricant to stop smearing.
Can Pb70Sn30 be welded?
Not arc-weldable; the alloy is itself a filler — join with soldering iron, torch or solder pot at 260–320 °C using rosin or zinc-chloride/acid flux on cleaned copper, brass, tinplate or steel.
Can Pb70Sn30 be formed, bent or molded?
Casts easily into bars, ingots and preforms and extrudes/rolls readily at room temperature; the 183–255 °C pasty range is what allows paddle-wiping and body-seam filling, but it also demands a firmly clamped joint until fully solid.
Pb70Sn30 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 |
|---|---|---|
| SnASTM B32 Alloy Sn30 | 29.5 – 31.5 | 30 |
| SbSn30A ≤0.12 %; Sn30B 0.20–0.50 % Sb | ≤ 0.5 | 0.2 |
| Bi | ≤ 0.1 | |
| Cu | ≤ 0.08 | |
| Ag | ≤ 0.02 | |
| Fe | ≤ 0.02 | |
| Zn | ≤ 0.01 | |
| Al | ≤ 0.01 | |
| As | ≤ 0.03 | |
| Cd | ≤ 0 | |
| Pbbalance, nominally 70 % | balance |
What surface finishes work on Pb70Sn30?
Filed, sanded and feather-edged easily for bodywork, then must be primed/painted or plated — bare surfaces oxidize dull grey, and any lead residue requires dust control and no food or potable-water contact.
Equivalent designations
Standards and trade names that resolve to Solder & Low-Melting Alloy Pb70Sn30 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B32 Sn30
- ISO
- 9453-116
- GB (China)
- HLSnPb30-70
How much does Pb70Sn30 cost?
Pb70Sn30 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.
Pb70Sn30 — frequently asked
What is Pb70Sn30 used for?
Pb70Sn30 is typically used for auto body filler solder, radiator seams, cable sheath joints and general low-stress soldering. In short: wide wiping pasty range; low-cost body-seam solder; lead-bearing, non-RoHS.
What is the yield strength of Pb70Sn30?
Pb70Sn30 has a typical yield strength of 22 MPa (3.19 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of solder & low-melting alloy grades.
Is Pb70Sn30 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 60% of solder & low-melting alloy grades). Practically never machined — extremely soft and gummy; if unavoidable use very sharp high-rake tools, high speed, low feed and paraffin/kerosene lubricant to stop smearing.
Can Pb70Sn30 be welded?
Not readily — weldability is rated poor (15/100). Not arc-weldable; the alloy is itself a filler — join with soldering iron, torch or solder pot at 260–320 °C using rosin or zinc-chloride/acid flux on cleaned copper, brass, tinplate or steel.
What surface finishes work on Pb70Sn30?
Filed, sanded and feather-edged easily for bodywork, then must be primed/painted or plated — bare surfaces oxidize dull grey, and any lead residue requires dust control and no food or potable-water contact.
Can Pb70Sn30 be formed, bent or molded?
Casts easily into bars, ingots and preforms and extrudes/rolls readily at room temperature; the 183–255 °C pasty range is what allows paddle-wiping and body-seam filling, but it also demands a firmly clamped joint until fully solid.
What is the maximum service temperature of Pb70Sn30?
Pb70Sn30 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 Pb70Sn30 cost?
Pb70Sn30 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
- ASTM B32 — Standard Specification for Solder Metal — ASTM International (2020)
- GB/T 3131 — (Tin-Lead Solder) — SAC / (2020)
- EN ISO 9453 — Soft solder alloys, chemical compositions and forms (alloy 116) — ISO (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Solder alloys) — ASM International (1990)
- ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Soldering section) — ASM International (1993)
- Tin-lead solder alloy property tables (bar, wire, cored wire) — solder producers (e.g. AIM, Indium Corporation, / ) (2023)
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.