A sander is a tool for smoothing or polishing wood and finishes using an abrasive-covered belt or disk. An electric sander is any of a number of types of power tool made for specialized jobs with this general purpose. Some of the most commonly found types of electric sander are belt sander, detail sander, disk sander, and orbital sander. There are also types of specialty sander for very specialized purposes, like metal finishing, pipe polishing, paint stripping, spindle sanding, burnishing, and drywall sanding.
A belt sander is an electric sander that spins a loop of sandpaper around two drums and can quickly remove material from the product. Because of this, they are usually used early in the process, i.e., they are not finishing sanders. They come in hand-held and stationary models, and because they produce so much sawdust, they are often sold with a cloth filter bag or a vacuum system to collect it. Some belt sanders have variable speed settings.
A detail sander is an type of electric sander for sanding in cramped areas and to achieve precise results. For this reason it may have features like a design to ensure low vibration, A variety of attachments or accessories—often various saw blades, knives, or rasps—can add to its usefulness.
A disk sander has a spinning wheel with sandpaper attached to its surface. It can be used on curved surfaces, whether for shaping or for removing rust, as on an autobody. The diameter of the disk on a disk sander is often 7 inches or 9 inches (17.78 cm or 22.86 cm), but they can come in other sizes as well, such as 5 inches or 6 inches (12.7 cm or 15.24 cm).
The type of electric sander known as an orbital sander comes in two varieties, both hand-held. The one known simply as an orbital sander uses a slow speed and a weight above a sanding pad to create a circular pattern of sanding in all directions. This approach is good for finishing. They come in ¼ and ½ sheet and other rectangular designs as well as having circular heads.
The random orbital sander, on the other hand, has two simultaneous motions, with the sanding disk both spinning and moving in an ellipse. This motion avoids the possibility of circular scratches and makes the random orbital sander desirable as a finishing tool. Some come with variable speed controls, which can make it suitable for use as a polishing tool, and dust collection.