The M4 Tube for metric thread screw is a mounting piece that is made of brass with a smooth finish in natural brass, which makes it also light-resistant. They are obtained in packages of 2,000 units of M4 tubes. Its internal thread design is designed to offer a fair and exact grip on furniture, shelves, cabinets, among others, to the M4 screws with metric thread and the M4 screws with extra-flat head, the objective is to facilitate the holding of these grip pieces in materials in which its installation is difficult. These types of tubes are embedded in the board, then the screws are threaded.