What is solder, which types, and how to choose tin-lead solder

The metal alloy material used to fill the weld, surfacing layer and brazing seam during welding is called solder. At present, there are mainly two types of solders: lead-free and lead-containing, and the forms include soldering wire, soldering rod, and solder. There is also semi-liquid solder paste. Lead-tin solder. Mainly tin-lead alloy, and some tin solder also contains a small amount of antimony. A tin alloy containing 37% lead and 63% tin is commonly called solder, with a melting point of about 183°C. This is the most common tin-lead soldering.The difference in the content of tin-lead and the added metal results in the difference in the melting point, thermal expansion coefficient, inherent stress and solidification time of tin-lead solder. Therefore, look at what you need and choose a solder with the right melting point and performance.