TABLE OF CONTENTS The subject of fasteners is an important one because these components are applied so frequently and employed in such large quantities. Although small, they perform important functions. In the design of tools and dies, fasteners are often the weakest link in the tool. If they are not selected and applied correctly, they can become the cause of failure of the entire tool or die.
In applying fasteners, an experienced designer seems to follow no rules for size, location, or number. But if two experienced designers were to select and apply fasteners for the same job, their choices would be almost identical. In turn, the checker would approve their selections.
Obviously, these professionals have developed a sense of proportion. When designers look over a layout and decide that the screws are too small, too close together, or too close to edges, they are subconsciously being guided by observations of tool components that failed and had the same proportions.
Fortunately, definite rules for application of fasteners can be used by the inexperienced designer or student to avoid many pitfalls. These pitfalls include hardening cracks and breaks, stripped threads, distortion by release of internal stresses, and misalignment of holes. By the use of these rules, the less experienced designer can avoid trouble and quickly develop a correct sense of proportion.
Figure 16.1 shows an exploded view of a typical die for producing blanks from metal strip. All fasteners have been shown removed from the components that they locate and hold. From...
