Polishing (metalworking)

Buffing are finishing processes for smoothing a workpiece's surface using an abrasive and a work wheel or a leather strop.

In metallography and metallurgy, polishing is used to create a flat, defect-free surface for examination of a metal's microstructure under a microscope.

To prevent further unwanted oxidization, polished metal surfaces may be coated with wax, oil, or lacquer.

The rough (i.e. large grit) passes remove imperfections within the metal surface like pits, nicks, lines and scratches.

This is achieved by moving the workpiece with the rotation of the buffing wheel, while using medium to light pressure.

To smooth out the finer marks, the surface is polished with a very fine (600) grit, copper plated, then buffed to a mirror finish with an airflow mop.

[citation needed] Polishing operations for items such as chisels, hammers, screwdrivers, wrenches, etc., are given a fine finish but not plated.

In order to achieve this finish four operations are required: roughing, dry fining, greasing, and coloring.

Wooden wheels have emery or other abrasives glued onto them and are used to polish flat surfaces and maintain good edges.

[5] Specific types include: sisal, spiral sewn, loose cotton, canton flannel, domet flannel, denim, treated spiral sewn, cushion, treated vented, untreated vented, string buff, finger buff, sisal rope, mushroom, facer, tampered, scrubbing mushroom, hourglass buff, rag, "B", climax, swansdown, airflow, coolair, and bullet.

In other applications such as pharmaceutical, dairy, and specialty plumbing, pipes are buffed to help prevent corrosion and to eliminate locations where bacteria or mold may reside.

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 ).