IN PREPARATION OF THIS CHAPTER, THE CONTENTS of the fourteenth edition were drawn upon. The author acknowledges the authors of the fourteenth edition. The current edition will review and update the topics as addressed by the previous authors, introduce new technology that has been developed, and include up-to-date references. The problem of resistance to abrasion exists all around us: on floors, walls, furniture, automobiles, farm implements, construction equipment, military gear, appliances, shoe soles, and so on. Because resistance to abrasion is a basic factor in the durability of a coating, its measurement is of practical importance to both producer and consumer. Abrasion is caused by mechanical actions such as rubbing, scraping, or erosion from wind and water. It can take two general forms: marring or wearing.