Make of high quality carbon steel.zinc plated. Flat head. Knurled body.Rust resistant and strength enough to apply in many kinds of heavy duty materials including sheet metal, steel, aluminum, plastic, fiberglass etc. Come with durable PP storage case with size/ type chart.Package include 300 pieces of rivet nuts.Metric sizes assorted in of M3, M4, M5, M6, M8, M10. Ideal kit to meet your multi-needs. These kit is lightweight, very convenient to carry; Meanwhile, the transparent storage box is durable enough to accommodate all items safely. The assorted nutserts are widely used in automotive, furniture, decoration and other electrical and industrial products, suitable for a variety of occasions such as in air conditioning, fire fighting, gas or in medicine beverage food chemical industry and metal sheets factory. Rivet nuts are made of carbon steel, strong rust and corrosion resistant for a long time use; Zinc plated surface help prevent surface damage and fade, anti-oxidation, healthy and lead-free, high strength, non-deforming, load-bearing threads Specification: Item Type: Rivet Nut Set Material: Carbon steel Specifications: M3, M4, M5, M6, M8, M10 Quantity: 300pcs Surface Treatment: Galvanized Application: Rivet nuts can be installed in a variety of materials, including steel, plastic and fiberglass Package List: 1 Box Rivet Nut Set 1 x Plastic Packaging Box