The wearing of metal parts might be defined as a gradual decay or breakdown of the metal. When a part becomes so
deformed that it cannot perform adequately, it must be replaced or rebuilt. While the end results of wear are similar, the causes
of wear are different. It is essential to understand the wear factors involved before making a hard surfacing product selection. It
would be easy to select a surfacing alloy if all metal components were subjected to only one type of wear. However, a metal part
is usually worn by combinations of two or more types of wear.