What class of fit are aircraft bolts usually manufactured with?

Aircraft bolts are typically manufactured with a Class 2 fit, which is the most common fit used in aviation applications. This type of fit allows for sufficient clearance for assembly, thermal expansion, and tolerances that ensure reliable performance under the various conditions experienced in aircraft operations. Class 2 fits strike an optimal balance between snugness and ease of assembly, leading to improved safety and performance in structural applications.

Class 3 fits are generally too tight for most aircraft applications, potentially leading to difficulties in assembly and maintenance, while Class 1 fits provide a looser tolerance that may not be appropriate for the precision required in aviation. Class 4 would be excessively loose, compromising the integrity and strength necessary for aircraft fastenings. Thus, Class 2 fits ensure both proper function and safety in the critical environment of aircraft construction and maintenance.