Features: 1.Made of high?quality carbon steel, high hardness, long service life, nickel?plated surface, good rust resistance and better performance. 2.It can be directly inserted into the aluminum slot of any assembly column, the rebound ball can fix its position, and the installation is simple and reliable. 3.Packing includes: 160PCS of 2020 series M3 x 50PCS, M4 x 50PCS, M5 x 60PCS, stored in a transparent plastic box, convenient for your storage and use. 4.Indispensable accessories for automobiles, easy to install and easy to operate, it can automatically locate and lock automatically. 5.Used for automobile, aluminum frame structure in construction industry, 3D printer, CNC milling machine, CNC laser cutting machine, robot project. Specification: Item Type: T Nut Material: Carbon steel Composition: M3 x 50PCS, M4 x 50PCS, M5 x 60PCS Surface Treatment: Galvanized Application: Used for automobile, aluminum frame structure in construction industry, 3D printer, CNC milling machine, CNC laser cutting machine, robot project