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.

Furthermore, self-drilling security screws are often made from durable materials like stainless steel or hardened steel, making them resistant to corrosion and tampering. This means that they can withstand harsh weather conditions and physical force, ensuring that they remain intact and secure over time.

Self-drilling screws, also known as Tek screws or self-tapping screws, are engineered with a drill bit tip that allows them to penetrate materials without the need for a separate drilling operation. This feature is particularly advantageous when working with thick steel, as it reduces the time required for assembly and helps ensure a secure, tight fit.