How much torque is typically lost to friction between the washer face of a nut and the flange surface on a plain alloy bolt and stud?

• A. 25
• B. 50
• C. 75
• D. 100

Answer: (B)

The typical amount of torque lost to friction between the washer face of a nut and the flange surface on a plain alloy bolt and stud is around 50. This is understood as a standard performance measure for bolted connections, reflecting the frictional forces at play when the nut is tightened.

Friction occurs because of the contact between the surfaces of the nut, washer, and flange. This resistance requires a certain amount of torque to overcome before the bolt begins to stretch and create a clamping force. In many engineering contexts, a loss of 50 units of torque is a general approximation that helps in calculating the necessary torque to achieve the desired tension on the bolt.

This understanding helps in the design and assembly of bolted connections, as recognizing the amount of torque that will be lost to friction allows for more accurate torque specifications in practical applications. By taking these losses into account, it ensures that assemblies are tightened appropriately to maintain structural integrity.