While you probably know that steel wool isn't made of wool, you might be surprised to learn that it doesn't necessarily contain steel either. These bundles of sharp-edged metal strips, which are used as an abrasive for sanding and scrubbing pots and pans, can be made of several different metals. Steel wool is generally made of low-grade carbon steel wire, aluminum, bronze or stainless steel. The metal is shaved into thin strands that, when bunched up in a fuzzy mass, resemble wool. Each strand of steel wool is made of thousands of metal fibers.
Since Victorian times, people have known that small pieces of metal can easily clean grease and grime off metal. Mechanics in the 19th century discovered that leftover metal shavings were good for cleaning metal. By the early 20th century, steel wool was being mass-produced, and when aluminum cookware came out around World War I, steel wool became an essential cleaning product in the American home. Although steel wool pads are replicated in the form of sponges with synthetic fibers, these cannot duplicate the scrubbing power of actual metal.
Steel wool comes in a variety of grades based on the coarseness of the metal, from extra fine to very course. The coarser the metal, the more abrasive it is; the finer it is, the less harsh it will be. The metal wires are bundled together in cluster, which are then amassed together in a large sheet. The sheet is folded and turned into pads. Steel wool pads for use in the kitchen generally have soap added to them for easy scrubbing and cleaning in one step.