self tapping sheet metal screws with rubber washer

The core of a chemical anchor lies in its two primary components the resin and the hardener. The resin, typically epoxy or methacrylate-based, is a liquid polymer that, when combined with the hardener, initiates a chemical reaction, leading to the formation of a solid, robust structure. The hardener, often a catalyst, accelerates this polymerization process, turning the liquid mixture into a rigid material capable of withstanding immense loads.

...

Self-drilling screws, as the name implies, eliminate the need for a separate drilling step, as they have a cutting tip designed to pierce through material without requiring a pilot hole. This not only saves time but also reduces the risk of material damage that can occur with traditional drilling methods. The 1 1 4 self-drilling screws refer to a specific size, which typically signifies a 1/4-inch diameter and a 4-thread pitch. The numbers '1' and '20' often represent the diameter in imperial measurements, while '4' indicates the number of threads per inch.

...

Expanding metal wall anchors are designed to hold heavy items by distributing the load across a larger area within the wall. They typically consist of a metal sleeve that expands when a screw is driven into it. This expansion action grips the surrounding material, creating a solid anchor point that can support significant weight. They are particularly useful in scenarios where traditional screws might loosen over time, such as in drywall installation or when hanging items from concrete surfaces.


...

The M12 in the term refers to the metric screw thread size, which measures 12 millimeters in diameter. This size is commonly used for medium to heavy-duty applications where robust anchoring is crucial. Chemical anchors, unlike mechanical anchors, rely on a chemical adhesive to create a strong bond between the anchor and the substrate. They offer advantages like high load-bearing capacity, resistance to dynamic loads, and minimal impact on the surrounding material.

...