Countersunk self-tapping screws are a type of screws with a flat head, countersunk head, or semi-countersunk head. Countersunk screws can also be called flat head screws, countersunk screws, semi-countersunk screws, and semi-countersunk screws. Generally, countersunk screws have cross grooves. Cross groove countersunk screws are commonly used in power equipment, electronic machinery, mechanical equipment, household appliances, digital products, water conservancy projects, decoration and construction, etc. Countersunk screws are generally made of metal screw wire, and the threads are rolled after forming. They are cylindrical and have a flat head, such as an inclined surface around the side of the screw, so that the screw can lock the nut or other objects.