A plate nut is stamped from a piece of sheet metal and contains two mounting holes that accept two blind rivets to hold the nut in a metal work piece. Located behind the forward plate is a cylindrical threaded tube that holds a threaded fastener to the work piece with the installed plate nut. When a plate nut is installed in a work piece, no tools are required to hold the back of the fasteners as an installer tightens a threaded fastener. The type of metal and installation environment will determine the type of metal plate nut required to provide a strong structural connection.
Stainless steel, carbon steel, copper, brass and nickel-plated are types of material used to make plate nuts. Each type of material has a specific use to ensure the installed nut is compatible with the base material and to ensure the installed nut does not fail due to corrosion, heat stress or electrolysis between different types of metal. Knowing the limits and the uses for each type of metal plate nut is the first step for an installer to provide an adequate connection in a given base material.
Softer metals—copper and brass—do not have the strength needed to hold high-stress connections, but their conductivity allows them to work in electrical environments as grounding points for wiring and electrical connectors. Hard metals—stainless steel, nickel-plated and carbon steel—provide strength to connections in high-stress environments or connections that hold excessive amounts of weight. Stainless steel and nickel-plated plate nuts add corrosion resistance to increased strength to provide a strong connection in moisture-prone areas or areas with chemical fumes in the air. Another component added to a plate nut allows the installed nut to resist loosening when subjected to vibrations and constant temperature changes.
Inside the threads of a locking plate nut sits a nylon insert that expands when a bolt is tightened in the nut. The expanded nylon material stops vibrations from traveling through the plate nut and to the threads of the bolt. A designation for the nylon material describes the maximum temperature the self-locking plate nut can be subjected to without the melting. When the nylon melts, it weakens and reduces the amount of vibration dampening provided by the installed self-locking plate nut. Thread locking compound may be applied to standard plate nuts to allow them to resist vibration when no self-locking nuts are available.