Potted Composite Inserts
There are two basic styles of inserts for honeycomb sandwich panels, potted-in (NAS) style versus press-fit / adhesive bonded composite inserts. The following page describes and depicts the potted inserts. These are commonly referred to as "Wall Panel Inserts" or "Floating Inserts" because they are widely used in aircraft walls and stowage bins to fasten panels to each other and to the aircraft structure. However, potted inserts can be used anywhere a fastener is desired, particularly where blind holes that do not pass all the way through the panel are needed or where inserts must be "flush" with the panel skin. In other words, there are no flanges, like that of a press-fit / adhesive bonded insert, to be glued to the top and bottom skins of the panel.
In the figure below, a hole is drilled into or through the panel and the potted insert is placed into the hole where the adhesive backed installation tab keeps it from falling all the way into the hole. In fact, when using blind inserts, an insert length should be selected that does not allowed the insert to touch the inner surface of the bottom skin. A minimum of 0.040 inches clearance is recommended to allow the adhesive to flow under and around the insert. The unique flow-control veins on MM's potted inserts prevent air pockets from occurring during adhesive injection into the hole. Air pockets are common with "old style" metal inserts, as the adhesive simply finds the path of least resistance and exits through the opposite vent hole without having to fill the entire hole.
Drawings now available in PDFs:Thru Thread
Request a quote for corrosion free composite inserts made of Torlon. Torlon fasteners have many benefits, including reducing time and labor costs. Marketing Masters also has Torlon clip nuts for use in the aerospace and aircraft industries.