Lead-Free Solder Bar for Industrial Soldering & Tinning
Lead-free solder bar is used where the product being assembled is required to be lead-free or your assembly requires a higher temperature solder. Common lead-bearing solder alloys have melting points of 361°F - 413°F, while Lead-Free solder bars melt at 426-590°F, depending on the alloy.
Lead-free solder bar melted into solder pots can be a faster, more automated method of soldering than hand-soldering with solder wire. Tri-Bar is a stick of solder that can be hand-held to provide a larger volume than wire solder for making soldered sheet metal seams. Solder pots that have a pump creating a wave are called wave solder machines or solder fountains. Static solder pots have no pump so you simply dip your part right into the surface of the solder.
WHICH LEAD-FREE SOLDER BAR SHOULD I USE ?
All lead-free solder bar alloys contain mostly Tin. Lead-free industrial solders have between 95% and 99.3% Tin, with the balance either Silver, Copper, Antimony or a combination. Pure Tin bar is recommended if you just need to Tin wires or component leads. Pure tin melts at 450°F and provides a protective coating on parts that enable them to be assembled with solder at a later time. Pure Tin is used alone in Solder Tinning Pots or can be added as a "sweetener" to lead-free alloys to adjust the pot blend.
For attaching parts together you need to use an alloy blend as the joint strength (inter-metallic bond) is higher with Silver or Copper mixed into the alloy. For the highest joint strength SAC305 or Sn96 lead-free alloys containing 3.0% or 3.7% Silver is your best choice. The silver content in these alloys, however, makes it more expensive. If cost is most important to you then 97/3 (with 3% Copper) or 99.3% Tin, 0.7% Copper alloys would be good choices.
For soldering automotive parts 97/3 lead-free solder alloy is widely used. The 3% Copper content in 97/3 gives it the highest electrical conductivity of any solder, better for assembling high amp electrical parts. For sheet metal assemblies requiring lead-free solder 97/3 alloy is the industry-approved solder alloy.