Thumb nuts are usually circular-shaped nuts with knurls on the sides to easily and quickly tighten without tools. A thumb nut is a type of fastener used to make mechanical joints between mating objects to ensure that they are held together securely. They are tightened with the help of thumb and fingers and do not require any tools, improving ease and decreasing installation time.
Thumb nuts are the best option when using a tool that is impossible due to space constraints or other causes. Thumb nuts also provide a decorative and finished look in applications where the fasteners are external and can be seen. These fasteners are commonly used in combination with a screw.
The externally threaded portion of thumb nuts comprises a cylindrical shaft with helical grooves that allow the nut to be advanced along the shaft when rotated. A thumb nut has a cylindrical shape and a center hole, with the same internal thread as the screw and a roughened external gripping surface for tightening.
Thumb nuts come in various styles and are available in standard and metric sizes. The size and type selected for a particular application depend on a few factors. These may include the environment, available space, external appearance, electrical properties, and more. Though thumb nuts are tightened by hand, they are usually smaller in size and are not used for large-scale or heavy-duty industrial fastening applications.
A standard thumb nut has a larger diameter piece with a knurled area to provide a gripping surface. Some are winged, with two or more flat sections that extend perpendicularly to the cylindrical part to provide a larger surface for tightening. The flat portion of thumb nuts is generally roughened with knurls or rough texture for better finger gripping.
Thumb nuts come in a variety of materials. Factors to consider in selecting the right thumb nut material are corrosion resistance, exposure to vibration, weight, and ability to resist.
These fasteners are generally used in aerospace, computer, consumer electronics, and telecommunication applications.
Thumb nuts are frequently used for protecting panels, components, or sub-assemblies that must be easily and quickly removed. They are also used in many electrical and electronic applications, like lighting and electrical mounting hardware inside electrical panels. Further examples include plumbing and automotive applications, where a wrench or other tool cannot be used due to space constraints.