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Alloy, diameter and flux core, and the alloy decides the iron temperature

The best solder wire for 2026

Solder wire is the metal that joins components to a circuit board, and three specifications decide how easy it is to use. The alloy comes first: leaded solders melt at a lower temperature and flow easily, lead-free alloys based on tin, silver and copper melt higher and are required for products sold in many markets. The melting point is published and sets the iron temperature. The wire diameter decides how much solder each touch delivers — fine wire for surface-mount parts, thicker wire for connectors and wires. The flux core cleans the joint as the solder melts; its type — rosin, no-clean, water-soluble — decides whether the residue must be cleaned off, and its percentage is published on the careful listings. Net weight of the reel sets the price per gram. Handling guidance matters: leaded solder calls for washing hands and not eating at the bench, flux fumes call for ventilation or extraction, and the maker's safety data sheet applies to both. Counterfeit solders sold under a recognised alloy name but with a different composition exist, and a listing that names the manufacturer's standard is more trustworthy. We compare alloy, melting point, diameter, flux type and percentage, net weight and handling guidance.

The parts and materials worth a place on the bench

  1. AIYHSW reel labelled Sn99.3 Cu0.7, flux 2.0 %, lead-free, WT 20 g, DIA 0.8 mm

    AIYHSW Lead-free solder wire Sn99.3 Cu0.7, 0.8 mm, 20 g, rosin core

    A 20 g reel of lead-free solder wire from AIYHSW in Sn99.3 Cu0.7, 0.8 mm thick, with a no-clean rosin core and a stated melting point of 227 °C, for cable, circuit board and small electronics repair.

    Alloy
    Sn99.3 Cu0.7, lead-free, title and first bullet
    Melting point
    227 °C, third bullet
    Diameter
    0.8 mm, title and first bullet
    Flux type and percentage
    Rosin core, no-clean formula, second bullet; the reel label in the product photograph reads FLUX 2.0 %
    Net weight
    20 g, title and first bullet
    Handling guidance
    Absent from the listing — “no toxic gas” and “no odour” are the seller’s wording, fourth bullet
    Amazon reference
    B0H6FHB7MX (same reference on 6 Amazon marketplaces)
    EAN
    0714047028612
    • Alloy, diameter and melting point all given
    • No-clean rosin core
    • Flux percentage only on the reel label

    Best for: An occasional repairer who needs a small reel of lead-free solder for cables and boards.

    ≈ 5 €
    Check price on Amazon
  2. Green CHANXUAN reel labelled lead-free, WT 30 g, flux 2.0 %, 0.6 mm ticked

    CHANXUAN Lead-free solder wire Sn99.3 Cu0.7, 0.6 mm, 2 % rosin flux, 20 g net

    A reel of lead-free Sn99.3 Cu0.7 solder wire from CHANXUAN, 0.6 mm with 2 % rosin flux and a melting point of about 227 °C, for a working temperature of 380 ± 20 °C, with 20 g of solder on a 30 g gross reel.

    Alloy
    Sn99.3 Cu0.7, lead-free, title and first bullet
    Melting point
    About 227 °C, third bullet
    Diameter
    0.6 mm, title and fifth bullet
    Flux type and percentage
    2 % rosin flux, low-residue formula needing no cleaning, first and fourth bullets
    Net weight
    20 g net, 30 g gross, fifth bullet; 30 g in the title
    Handling guidance
    Absent from the listing — a working temperature of 380 ± 20 °C is given, third bullet
    Amazon reference
    B0GZ2MHTH5 (same reference on 5 Amazon marketplaces)
    EAN
    0761578230731
    • A working temperature given: 380 ± 20 °C
    • Flux share stated: 2 % rosin
    • 30 g in the title is the gross weight; 20 g is solder

    Best for: A maker soldering small pads and SMD leads who wants a fine wire and an iron setting to start from.

    ≈ 6 €
    Check price on Amazon
  3. Blue WUHANDAT reel labelled WT 50 g, flux 2.0 %, Sn99.3 Cu0.7, 1.0 mm ticked

    WUHANDAT Lead-free solder wire Sn99.3 Cu0.7, 1.0 mm, 2 % rosin flux, 30 g net

    A reel of lead-free Sn99.3 Cu0.7 solder wire from WUHANDAT, 1.0 mm with a 2 % rosin-core flux and a melting point of 227 °C, carrying 30 g of solder on a 50 g gross reel.

    Alloy
    Sn99.3 Cu0.7, lead-free, title and second bullet
    Melting point
    227 °C, fourth bullet
    Diameter
    1.0 mm, title and first bullet
    Flux type and percentage
    2 % rosin-core flux, second bullet
    Net weight
    30 g net, 50 g gross, first bullet; 50 g in the title
    Handling guidance
    Absent from the listing
    Amazon reference
    B0H14YWVQP (same reference on 4 Amazon marketplaces)
    EAN
    0761578230816
    • Flux share stated: 2 % rosin core
    • A 1.0 mm wire for general joints
    • 50 g in the title is gross; 30 g is solder

    Best for: A maker soldering wires and through-hole parts who wants a thicker lead-free wire.

    ≈ 9 €
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  4. Unbranded green reel labelled lead free solder wire, WT 100 g, flux 2.0 %, 1.0 mm ticked

    Ka wah core Lead-free silver solder wire Sn99 Ag0.3 Cu0.7, 1.0 mm, 2 % flux, 100 g

    A 100 g reel of lead-free solder wire from Ka wah core in Sn99 Ag0.3 Cu0.7 with a 2.0 % rosin-core flux, 1.0 mm thick and a stated melting point of 217 °C, for ICs, circuit boards and hobby soldering.

    Alloy
    Sn99 Ag0.3 Cu0.7, lead-free, first bullet
    Melting point
    217 °C (422.6 °F), second bullet
    Diameter
    1.0 mm (0.039 in), title and second bullet
    Flux type and percentage
    Rosin core, 2.0 %, first bullet
    Net weight
    Absent from the listing — 100 g gross, second bullet
    Handling guidance
    Absent from the listing — lead-free wire is called safer than leaded, fourth bullet
    Amazon reference
    B0BX9G3WDQ (same reference on 5 Amazon marketplaces)
    EAN
    0732214071186
    • A silver-bearing alloy at a stated 217 °C
    • Flux share stated: 2.0 %
    • Weight given as gross only

    Best for: A hobbyist who solders regularly and wants a silver-bearing lead-free wire in a larger reel.

    ≈ 16 €
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  5. FELDER ISO-Core Ultra-Clear reel, 0.50 mm, 0.100 kg, 2.2 % flux, Sn100Ni+, distributed by GALLUNOPTIMAL

    GALLUNOPTIMAL Lead-free solder wire Sn100Ni+, 0.5 mm, 2.2 % halogen-free flux, 100 g, made by FELDER

    A 100 g reel of Sn100Ni+ lead-free solder wire from GALLUNOPTIMAL, made by FELDER in Germany: Sn99.25 Cu0.7 Ni0.05, 0.5 mm, with 2.2 % halogen-free Ultra-Clear REL0 active flux and a melting point of 227 °C, to EN ISO 9454-1.

    Alloy
    Sn100Ni+, micro-alloyed Sn99.25 Cu0.7 Ni0.05, lead-free, first bullet; the reel label in the product photograph reads Sn99.3CuNiGe
    Melting point
    227 °C, third bullet
    Diameter
    0.5 mm, title and fourth bullet
    Flux type and percentage
    2.2 % Ultra-Clear active flux, REL0, halogen-free, second bullet
    Net weight
    100 g reel, title and fourth bullet
    Handling guidance
    Absent from the listing — EN ISO 9454-1 and 1222 named, fifth bullet
    Amazon reference
    B0F8JFHR8M (same reference on 6 Amazon marketplaces)
    EAN
    4250078313038
    • Full alloy with nickel micro-addition: Sn99.25 Cu0.7 Ni0.05
    • Flux class given: REL0, halogen-free, 2.2 %
    • No handling guidance

    Best for: A maker soldering fine electronics who wants an alloy and flux described to a standard.

    ≈ 19 €
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  6. goobay 40845 reel labelled 250 g, 0.3 % silver, lead-free, 1.0 mm

    goobay Lead-free silver solder wire Ag0.3 Cu0.7, 1 mm, 2.5 % no-clean flux, 250 g

    A 250 g reel of lead-free silver solder wire from goobay, 1 mm, with 0.3 % silver, 0.7 % copper, 96.5 % tin and 2.5 % halogen-free no-clean flux, a melting point of 217 °C and low smoke stated, for cables, boards and appliance repairs.

    Alloy
    96.5 % tin, 0.3 % silver, 0.7 % copper, lead-free, title and first bullet
    Melting point
    217 °C, title and first bullet
    Diameter
    1 mm, title and first bullet
    Flux type and percentage
    2.5 % no-clean flux, halogen-free, first and second bullets
    Net weight
    250 g reel, title and first bullet
    Handling guidance
    Absent from the listing — low smoke during soldering stated, third bullet
    Amazon reference
    B07RWKLB92 (same reference on 5 Amazon marketplaces)
    EAN
    4040849408458
    • A 250 g reel
    • No-clean, halogen-free flux at 2.5 %
    • No handling guidance beyond low smoke

    Best for: A regular solderer or small repair bench that goes through lead-free wire steadily.

    ≈ £37 / 32 €
    Check price on Amazon

A price quoted in the text of a MakerVerdict page dates from the day that page was written; the live figure beside each product is fetched while you read and replaces it.