They are frequently used in machinery and appliances.
Machine Screw, Metric, Flat Head, Phillip Drive M6-1.0 X 20MMFlat Head, Phillips DriveUse with nuts or pre-threaded holes of the same diameter & thread sizeOften used in machinery & appliancesNuts and washers not includedThread Type: Coarse, Thread Class: 6G, Point Style: BluntSpecification(s) Met: DIN 965 Machine screws have a uniform diameter along their entire length and are designed to screw into threaded holes or to be used in combination with machine screw hex nuts.