1. quality Material – The M3 black hexagon flat head screw set is made of quality alloy steel. The alloy steel material is strong and durable, with good corrosion resistance in harsh environments such as temperature, cold, and humidity. The screws have rust prevention and antioxidation capabilities, ensuring longterm use. 2. Safe and Environmentally Friendly – Our M3 black hexagon flat head screws are made of environmentally friendly and nontoxic quality materials. No harmful substances will be released during use, ensuring your safety. 3. Sharp Threads – The screw threads are sharp, clean, and precise. The compact threads are not easily deformed or slipped during the rolling process, fully meeting the standardized metric specifications. 4. Wide Applications – The M3 black hexagon flat head screw set is suitable for professionals, hobbyists, landlords, craftsmen, repairmen, carpenters, construction, plumbing, HVAC, etc. They are also suitable for 3D printing projects and are an ideal choice for replacing lost or damaged screws. They can be used for metal plates and wood. This set is a tool for both home and workplace, and multiple sizes can meet your maximum needs.