Bolts are fundamental components in mechanical engineering and structural design, providing vital connections that hold various elements together. The bolt structure, which includes its design, material properties, and functional characteristics, plays a crucial role in ensuring the stability and integrity of numerous applications ranging from machinery to bridges.

The M in M20 signifies that it is a metric bolt, aligning with the International System of Units (SI). The number 20 denotes that the nominal diameter of the bolt is 20 millimeters. Foundation bolts are typically made from high-strength materials, such as structural steel, to ensure they can withstand substantial loads and resist environmental factors.

In automotive applications, metal expansion nuts are utilized in securing engine components and exhaust systems, where high temperatures can lead to expansion. Their reliability ensures that parts remain firmly attached, reducing the risk of failure.

- Buildings In the construction of skyscrapers and industrial buildings, A325 fasteners are essential for connecting steel beams and columns, providing the necessary support and resilience against wind and seismic forces.