Which materials are commonly found in soft solders?

Soft solders are primarily made of tin and lead due to their unique combination of properties that make them suitable for various soldering applications. Tin has a moderate melting point, which allows for easy manipulation and joining of different metals without causing significant thermal stress. Lead, on the other hand, lowers the melting point of the solder alloy further, making it even easier to work with.

This combination not only allows for effective joining of electrical and electronic components but also enhances the solder's ability to flow into tight spaces and create strong bonds. Historically, soft soldering using tin-lead alloys has been the standard in electronics due to its proven reliability and performance.

In contrast, other options like silver and copper or gold and nickel are generally used in harder solders or as coatings rather than in soft solders because they have higher melting points and are more expensive. Aluminum and zinc are less common in soldering because of their higher melting points and different bonding characteristics, which can complicate the soldering process for standard applications.