What is the nominal diameter of an oversized bolt hole for a 1 inch diameter bolt?

The nominal diameter of an oversized bolt hole for a 1-inch diameter bolt is indeed 1-¼ inches. The purpose of oversized bolt holes is to accommodate a certain amount of clearance around the bolt, which is necessary for several reasons such as ensuring proper alignment, allowing for installation tolerances, and accommodating variations in bolt size.

For a bolt that is 1 inch in diameter, the typical practice is to add an additional ¼ inch to the nominal diameter to create an oversized hole, resulting in a total diameter of 1-¼ inches. This standard increase is commonly used in structural applications to ensure that there is enough space around the bolt for proper function and safety.

Understanding this standard for oversized bolt holes is crucial for those working in structural steel and bolting, as it directly impacts the integrity of the connections and the overall performance of the structure.