double ended hex bolt

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.

...

In conclusion, ceramic-coated self-drilling screws represent a significant advancement in the field of construction fasteners. Their combination of hardness, corrosion resistance, and wear resistance makes them an excellent choice for a wide range of applications. By increasing productivity, reducing maintenance costs, and enhancing the longevity of structures, these screws are helping to drive efficiency and sustainability in the construction industry.

...