Polishing (metalworking)

"Buffing" redirects here. For nail polishing, see Nail buffing. For other uses, see Buff.
A tarnished and unpolished silver bowl (left) and a polished silver piece (right). There is a visible difference in cleanliness and color. The piece held above the two bowls has also been polished. (These pieces are part of an 18th-century silver epergne in the collection of the Indianapolis Museum of Art).

Buffing are finishing processes for smoothing a workpiece's surface using an abrasive and a work wheel or a leather strop. Technically, polishing refers to processes that uses an abrasive that is glued to the work wheel, while buffing uses a loose abrasive applied to the work wheel. Polishing is a more aggressive process, while buffing is less harsh, which leads to a smoother, brighter finish.[1] A common misconception is that a polished surface has a mirror-bright finish, however, most mirror-bright finishes are actually buffed.

Polishing is often used to enhance the appearance of an item, prevent contamination of instruments, remove oxidation, create a reflective surface, or prevent corrosion in pipes. In metallography and metallurgy, polishing is used to create a flat, defect-free surface for examination of a metal's microstructure under a microscope. Silicon-based polishing pads or a diamond solution can be used in the polishing process. Polishing stainless steel can also increase its sanitary benefits.

The removal of oxidization (tarnish) from metal objects is accomplished using a metal polish or tarnish remover; this is also called polishing. To prevent further unwanted oxidization, polished metal surfaces may be coated with wax, oil, or lacquer. This is of particular concern for copper alloy products such as brass and bronze.[2]

While used less extensively than traditional mechanical polishing, electropolishing is an alternative form of polishing that uses the principles of electrochemistry to remove microscopic layers of metal from a base surface.[3] This method of polishing can be fine-tuned to give a wide range of finishes, from matte to mirror-bright. Electropolishing also has an advantage over traditional manual polishing in that the finished product will not experience the compression and deformation traditionally associated with the polishing process.

  1. ^ Oberg, p. 1439.
  2. ^ Deck, Clara, The care and preservation of historical brass and bronze, retrieved 2009-01-06.
  3. ^ "What is Electropolishing?"