Steel wool, also known as wire wool or wire sponge, is a bundle of strands of very fine soft steel filaments. It is used as an abrasive in finishing and repair work for polishing wood or metal objects, cleaning household cookware, cleaning windows, sanding surfaces, and to produce sparks while burning in light painting.
Steel wool is made from low-carbon steel in a process similar to broaching, where a heavy steel wire is pulled through a toothed die that removes a thin wire shaving.
Steel wool is commonly used by woodworkers and craftsmen working with paint, lacquer and varnish.
Steel wool is often used for professional cleaning processes, not only on wooden surfaces, but also on glass,because it is softer than these materials.
Another use for steel wool is in rodent control. Small holes are plugged with coarse grade steel wool, which, if gnawed on by rodents, causes extreme pain in the mouth and, if ingested, severe internal damage leading to death.
When steel wool is heated it increases in mass due to the combination of burning iron with oxygen.
Very fine steel wool is sometimes carried for use as tinder in emergency situations, as it burns even when wet and can be ignited by fire, a spark, or by connecting a battery to produce joule heating.