In photovoltaic (PV) installations, various types of nuts may be used depending on the specific components and mounting systems being employed.  Some common types of nuts used in PV installations include:

Hex Nuts: These are standard nuts with six sides and are widely used in PV installations for securing bolts or screws.

Nylock Nuts: Nylock nuts have a nylon insert that helps prevent them from loosening due to vibrations, making them suitable for use in PV systems where stability is crucial.

Flange Nuts: Flange nuts have a built-in washer-like flange that distributes the pressure and prevents the nut from loosening, making them useful in PV installations where a secure fit is needed.

T-Slot Nuts: T-slot nuts are designed to fit into T-slot aluminum extrusions commonly used in PV mounting systems, allowing for easy adjustment and secure attachment of components.

Wing Nuts: Wing nuts have two large wings that allow for hand tightening, making them convenient for quick adjustments or temporary installations in PV systems.

Cage Nuts: Cage nuts are often used in rack-mounted PV systems where they fit into square holes on the mounting rails, providing a threaded insert for securing bolts.