[Constitute] Made of carbon steel, Nickel plated, rust resistant and strong enough to apply in many kinds of heavy duty materials including steel, plastic and fiberglass. They are internally threaded and T- Hammer Head Nut slot that can be anchored fully sideways. These nuts have high hardness and long service life. [A large quantity] T-slot nuts can be installed in many types of materials, including steel, plastic and fiberglass . Each set includes many pieces of T-slot nuts, so you don’t have to go to the hardware store to look for rivet nuts for a while. There are total 50pcs nut which you can use for many projects. [Easy to use] They are simple to use and convenient to connect aluminum profiles to other parts. Convenient to install, designed to bulge out the back of the panel like a screw is tightened in its threads. they can be applied to fix the tub, mount the storage containers against the rear door and anchor on the wheel wells; Use nut installation tools to make work easier