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.

2. Application Suitability In environments where higher loads or forces are expected, such as in industrial settings or high-rise buildings, 4% anchor bolts are often preferred. Conversely, 3% bolts may be sufficient for lighter applications, such as residential projects.