Page 82 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

Chapter 3 Screw It or Glue It: Fastening and Joining Parts 63

FIGURE 3-9 Specialty screws

Nuts

Nuts thread onto the end of screws and are the easiest way to form a bolted joint.
Choose a nut with the same thread size and pitch as your screw or it will not fit. The
following are some types you might use in your projects:

• The most common nut is called a hex nut.
• Next most common in usefulness is a locknut. Locknuts have a nylon insert
or deformed thread that makes them vibration-resistant and very secure.
However, they are generally not reusable.
• Wing nuts are great if you need to assemble and disassemble connections
without tools.
• Tee nuts are ingenious little components that you can hammer into a hole in
wood and soft plastics to create metal internal threads with little effort.
• Rivet nuts do the same job as tee nuts in sheet metal assemblies, but require
a special installation tool and are not easily removable once installed.

Washers
Washers serve at least four purposes:

1. Allow you to avoid marring the base material during installation

2. Spread the screw fastening force over a larger area