RENY M3 is a metric screw thread size, and M3 screws, bolts, nuts, and washers made of polymer materials may be used in a variety of applications where a lightweight and corrosion-resistant fastener is needed. M3 screws have a 3 millimeter diameter and a thread pitch of 0.5 millimeters. Polymer materials are often chosen for their lightweight and corrosion-resistant properties, making them suitable for use in a variety of applications where metal fasteners may be too heavy or prone to corrosion. M3 nuts and washers are used to secure M3 screws and bolts in place. Washers are flat rings that are used to distribute the load of a fastener and to prevent damage to surfaces. Nuts are used to fasten bolts and screws together and are typically tightened using a wrench.