Premium washers: the premium washers from are made of 304 stainless steel for a long service life. The surface and edges are smooth, have excellent oxidation and corrosion resistance, are suitable for use in any environment and not easy to deform. Package and size: this set contains 100 high-precision manufactured M4 x 12 mm washers DIN9021. The dimensions of our washers are 4.3mm inner hole diameter, 12mm outer diameter (AD), 1mm thickness. Note: Please check the size of your penny washers before purchasing! Practical function: our washers are perfectly compatible with screws, nuts and bolts to prevent pulling through. Proper use of washers increases the contact area between screw head and material and distributes weight to prevent leakage and loosening. Minimizes friction and heat during the turning process to avoid damage to the material surface and thus provide better protection. Easy to install: our washers have a recessed design that fits better with the screws and provides high tensile strength. The size of the washers is almost the standard. Simply choose the appropriate hole size based on our size information, place it under the screw and turn the screw. Wide applications: our washers are practical accessories in many areas, e.g. in mechanical engineering, mechanical engineering, automotive construction, electronics and more. These washers can be used around the home, shed, factory, woodworking or metal workshop. They are ideal for repairing fences, electrical connections, mounting fixtures and sheet metal work.