A screw is a round rod like part. The “rod” has a head. The end opposite to the head is called the point. The part between the head and point is the externally threaded shank. With the threads, the screw can be turned into pre-tapped holes or nuts with mating threads. Sharp and hard point machine screws can drill directly into parts without pre-drilled holes. (3.1.2.1 ASME B18.12, No. 2401 JIS B0101, BS1981)A machine screw is a screw threaded for assembly with a preformed hole with mating internal threads tapped in advance. Machine screws are generally furnished with plain points, but other types of points are allowed for special purposes. Machine screws are usually small ones. (3.1.2.13 ASME B18.12, No. 2402 JIS B0101 & BS1981) Specifications: DIN84, DIN85, DIN963, DIN965, DIN966, DIN7985, DIN7991? ASME B18.6.3 & SAE J82, IFI-513, ASME B18.6.7M ISO14580, ISO14581, ISO10642 JIS B1101, JIS B1107, JIS B1111, JIS B1136, BS4183/450/1981, AS/NZS1427/B50, UNI7687/7688 NF E25-107～111, NF E25-119～123, NF E25-127～129