When working with sheet metal, rivnuts are often used to fasten panels together, attach hardware, or mount items to other surfaces. Rivnuts (rivet nuts) are often thought of as an alternative to welding; however, rivnuts do not actually melt any material during the joining process. Instead rivnut installation tools use grooves in rivnut rims to pinch together two pieces of metal so they can be permanently joined.
Rivets typically have a flat head on one side and a smaller diameter through which you can insert another fastener or piece of material for additional support. Rivet nuts have hexagonal “teeth” around their center opening that interlock when installed together, forming a much stronger connection than rivnuts.
To rivnut a metal sheet, rivnut installation tools are used to create several indents in the rivnut’s outer rim that act as gripping prongs for installation. The rivnut tool is pushed into the rivnut several times, creating grooves that will allow it to be permanently joined with another piece of material. Rivets are installed using either an rivnut installer or an riv- nut riveter. Both types of tools install rivnuts by compressing the rims together, which deforms the hexagonal teeth on one side and pushes them outwards towards their mating part (in other words, both sides interlock). The difference between these two tools is that an rivnut riveter uses a pneumatic plunger to install rivnuts at high speeds, while an rivnut installer is manually operated.
Rivets are typically used on sheet metal projects because the installation process joins the rivnut rims together through small indentations in their outer rims, but does not actually distort or melt any of the materials being joined. Rivets are also often preferred over welding for use with dissimilar metals that may have different thermal expansion rates that can cause them to fall apart if welded together. The strength of rivnuts comes from this ability to join two pieces of material without distorting either one; this means they can be used with metal panels as thin as 0.8mm (.031 in.).
Rivnuts are typically installed when two or more pieces of sheet metal will be joined together permanently, but rivnuts can also be used to mount assembly hardware for machine components. Although rivnuts can be made from stainless steel, rivnut installation tools should not be used with rivnuts that are over 1/16-inch thick because the rims will spread too much during installation and may become unusable. Rivet nuts cannot be removed once installed, so it is important to verify their suitability for your project before beginning.