Fasteners for Sandwich Structure
Inserts are potted or mechanically installed in sandwich material, like honeycomb, to allow fabrication of aircraft interior secondary structures, such as: stow bins, galleys, and lavatories. Insert types include threaded or nonthreaded, through or blind, locking or nonlocking. Floating inserts feature a nut component that can move to compensate for screw misalignment.

Spacers are installed in structural applications, most typically in aircraft floors. Spacers are either one-piece or a two piece system of plug and sleeve. Often spacers are installed with epoxy under the flange to increase shear load carrying capability.