Close tolerance bolts are used where?

• A. Precision sized used where tight fit is required due to load reversals and vibration
• B. For cosmetic appearance
• C. For easy removal
• D. For general purpose applications

Answer: (A)

Close tolerance bolts are used where a precise fit is essential to maintain alignment and preload under dynamic conditions. When loads reverse and vibration occurs, any clearance can allow movement and loosening, so tight tolerances keep threads fully engaged and clamp force stable, reducing movement and fatigue risk. This makes them the right choice for applications requiring a reliable, consistent hold under such conditions. Cosmetic appearance, easy removal, or general-purpose use don’t demand or justify the extra precision, and would typically rely on looser tolerances or different fastener features.