Steel wool, also known as iron wool, wire wool, steel wire or wire sponge, is a bundle of very fine and flexible sharp-edged steel filaments. It was described as a new product in 1896. It is used as an abrasive in finishing and repair work for polishing wood or metal objects, cleaning household cookware, cleaning windows, and sanding surfaces.
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 thin, sharp, wire shavings.
Steel wool is commonly used by woodworkers, metal craftsmen, and jewellers to clean and smooth working surfaces and give them shine. However, when used on oak, remaining traces of iron may react with tannins in the wood to produce blue or black iron stain, and when used on aluminium, brass, or other non-ferrous metal surfaces may cause after rust which will dull and discolour the surface. Bronze wool and stainless steel wool will not cause these undesirable effects.
Steel wool is often used for professional cleaning processes on glass and porcelain because it is softer than those materials and is able to scrape off deposits without scratching the underlying surface like common abrasives. In many countries, soap-impregnated steel wool pads were sold under various trade names for household cleaning, although those products sometimes no longer contain steel wool.