solder

Imagine you are fixing a circuit, joining a copper pipe, or making a piece of jewelry. You need something that can melt, flow into a small gap, and then cool into a firm joint. That is what solder is. It is a metal alloy with a lower melting point than the metal parts being joined, so it can hold them together without melting the main pieces.

People use it in electronics, plumbing, and metalwork. As a verb, "solder" means to join parts in this way. It is not the same as welding, because welding melts the main metal itself, while soldering adds a filler metal that flows between the parts. A soldering iron or torch provides the heat needed to do the job.

Solder is a metal alloy used to join metal parts in a process called soldering. Traditionally, many solders were made from tin and lead, but today lead-free types are also common. The key idea is that this alloy melts at a lower temperature than the pieces being joined. That lets it flow into the gap between the parts and then harden into a secure joint without melting the main metal.

If you picture someone repairing a circuit board, sealing a copper pipe, or joining small pieces of silver in a workshop, you are picturing common uses of solder. The process usually involves heating the joint with a soldering iron or, in some kinds of work, a torch. When the alloy melts, it spreads over the prepared surfaces and bonds them as it cools. In electronics, this often creates both a mechanical hold and an electrical connection. In plumbing or jewelry work, the goal is usually a neat, lasting join.

As a verb, "solder" means to join something using this melted alloy. The word is often contrasted with "weld" because welding melts the main metal, while soldering normally does not. Over time, the materials used for solder have changed because of health and safety concerns, especially around lead. Modern solder may contain tin along with metals such as copper, silver, or bismuth. In everyday use, the word can refer either to the alloy itself or to the act of joining metal with it.