4. Corrosion Resistance Mechanical fasteners often create points of vulnerability where corrosion can occur, especially when dissimilar materials are joined. Bonded fasteners provide a continuous seal that can prevent moisture intrusion, thereby reducing the risk of corrosion and extending the lifespan of the assembly.

2. Enhanced Holding Power The wide wafer head design allows for a larger contact area with the material, which improves the holding power of the screw. This is particularly beneficial in applications where resistance to pull-out forces is critical.

The terms 3% and 4% often relate to the percentage of the anchor bolt’s yield strength in relation to the concrete’s compressive strength. For example, a 3% concrete anchor bolt means that the bolt can withstand loads up to 3% of the concrete's yield strength, while a 4% bolt can handle loads up to 4%. This distinction is vital for engineers and contractors, as it influences load calculations, safety factors, and the overall design of the structure.

An M20 bolt generally has a thread pitch of 2.5 mm, which offers a good balance between load-bearing capacity and ease of installation. These bolts can come in various lengths to suit different applications, making them adaptable to various construction projects.