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How do cap screws and machine screws clamp parts together?

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A diagram displays six types of simple machines with labeled illustrations: inclined plane, wedge, screw, lever, wheel and axle, and pulley, each shown with real-world examples like ramps, axes, screws, seesaws, door handles, and pulleys lifting objects. — simple machine Six simple machines for transforming energy into work.

Cap screws and machine screws function as fasteners by clamping machine parts together. This process occurs either when one of the parts contains a threaded hole or when the screw is used in conjunction with a nut.

When these screws are tightened, they undergo a process of stretching. This stretching generates a tensile load, which effectively clamps the components together. While both are used for similar purposes, machine screws are generally produced in smaller sizes than cap screws and typically feature heads designed for use with a screwdriver.1