TABLE OF CONTENTS Rotary burs are widely used to deburr holes as well as provide precision chamfered edges. They are found in almost every plant's arsenal of burr-fighting weapons. As this section shows, there are literally hundreds of tools from which to choose.
They are known not only as burs but also as rotary files, mills, cutters and combinations of these and many other names. As Fig. 3-90 illustrates, one of the principal differences between a bur (Fig 3-90b) and a conventional countersink (Fig 3-90a), or similar cutter, is that a bur has a relatively large number of small teeth. In many cases a rotary bur has 2 5 times more teeth than a typical countersink tool. These many small teeth give the bur its smooth finishing action. The small teeth prevent excessive cutting into edges and reduce chatter that, in turn, improves surface finish. These tools can be used at high cutting speeds, which increases the number of edges that can be finished in a given time.
There are two types of burs. Industrial burs typically are relatively large (1/4 2 in. diameter). Dental burs, which are very small, represent the second type of bur. Dentists use them to work on teeth. These distinctions are not hard and fast, and many catalogs intermix these tools or do not identify them by typical usage. Miniature bur balls only 0.004 in. (0.1 mm) diameter are available. The smallest standard...
