TABLE OF CONTENTS Surface texture or finish refers to the degree of smoothness, or roughness, on any surface of a machine part. There are many reasons for specifying and controlling surface texture. The way some parts function is primarily determined by their finish. A ball bearing must have smooth surfaces to reduce friction. An automobile must have an engine block with smooth cylinder walls to run efficiently. The handles on a pair of pliers must be rough, on the outside, so they will not slip in your hand. Surface texture affects appearance, friction, lubrication, sealing, wear, and many other characteristics.
The performance of many products with moving parts depends on the finish of their contacting surfaces. A machine part may require more than one grade of smoothness on different surfaces. An automobile engine block must have very smooth cylinder walls; other areas do not have to be as smooth, while some surfaces on the block do not require any special finish.
Surface texture will be examined by reviewing the following:
The definition and characteristics of surface texture.
How is surface texture displayed on industrial prints.
How is surface texture measured.
Before examining the details, a brief history of the subject will be reviewed.
Over the years, surface finishing has gone through many changes. All the methods of identifying, producing, and checking surface texture have gone through many improvements. The original finish symbol was a small f, which indicates a smooth finish, and is still in limited use. The term smooth is...
