Soldering is useful for electronics to create a strong physical connection between metals. A soldering iron — also called a soldering pencil — is the basic tool for soldering.
Here are some things to look for when purchasing a soldering iron:
The wattage rating should be between 20 and 50 watts. Note that the wattage doesn't control how hot the soldering iron gets. Instead, it controls how fast it heats up and how fast it regains its normal operating temperature after completing each solder joint.
Each time you solder, the tip of the soldering iron cools a bit as it transfers its heat to the wires you're joining and to the solder itself. A higher-wattage soldering iron can maintain a stable temperature longer while you're soldering a connection and can reheat itself faster in between.
The tip should be replaceable. When you buy your soldering iron, buy a few extra tips so you'll have replacements handy when you need them.
Although you can buy a soldering iron by itself for under $10, spend a few more dollars and buy a soldering station that includes an integrated stand. A good, secure place to rest your soldering iron when not in use is essential. Without a good stand, your workbench will soon be covered with unsightly burn marks.
A ground three-prong power plug is desirable, but not essential.
The grounding helps prevent static discharges that can damage some sensitive electronic components when you solder them.
More expensive models have built-in temperature control. Although not necessary, temperature control is a nice feature if you'll be doing a lot of soldering.