Many screws are required primarily because of their strength, and they are a particular size, length and material because they require a high torque strength, ie. they are fastened tightly to hold materials together under great force and pressure. Machine screws are slightly different, in that, although they are very strong, this is not their primary characteristic.

Machine screws are typically quite small and are usually used in electronic components and equipment, in engines and automotive assembly, and usually to hold metal panels together. In other words they are screws used in machines. So they aren’t going to be under great pressure, but they do need to be secure and reliable, and because machine screws are used in assembly lines for vehicles and other production parts, they require precise and consistent manufacture.