Kester part number 24-9574-6403 K100LD is a lead free solder wire with 99.3% tin and 0.7% copper composition, offered in 0.031 inch diameter with 3.3% 331 rosin activated flux. This water soluble formulation is engineered for precision PCB assembly, electronics rework, through hole soldering, and component repair work where consistent wetting and reliable joints are essential. The 331 flux system provides excellent flow characteristics and minimal residue cleanup, making it a trusted choice for professional electronics shops and serious hobbyists who demand repeatability and quality. RoHS compliant and made in the USA, this solder delivers the performance standards required for demanding production and repair environments.
Ultra fine sized diameter useful for precision soldering and micro electronics.
.015" (0.4 mm)
Very fine sized diameter useful for precision soldering and jobs requiring small amounts of solder.
.020" (0.5 mm)
Fine sized diameter used for through hole and and surface mount work. Delivers a Controlled amount of solder.
.025" (0.6 mm)
Ideal for standard circuit board components where precision is needed but not ultra-fine work.
.031" (0.8 mm)
Ideal for fixing circuit boards, replacing components, and general rework. Popular for Arduino, Raspberry Pi, and DIY projects. It's a versatile diameter, often called the "sweet spot" for electronics.
.040" (1.0 mm)
Perfect for surface-mount devices (SMDs) and medium components where precision is key but more solder is needed.
.050" (1.27 mm)
Used for various tasks where a balance of flow and control is required, like general electrical repairs.
.062" (1.5 mm)
medium-thickness wire ideal for general electronics, larger through-hole components, appliance repair, automotive work, and crafts like stained glass
.093" (2.36 mm)
versatile, medium-to-thick wire used for general and heavier-duty electrical, electronics, automotive, and HVAC repairs/manufacturing.
Size guide text
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