What type of lockbolt features a collar that is swaged onto the locking grooves?

The correct answer is that both types of lockbolts—flush head and protruding head lockbolts—can feature a collar that is swaged onto the locking grooves.

In the context of aerospace assembly, lockbolts are utilized for their reliability and strength in fastening structural components. The collar plays a critical role in the locking mechanism. When swaged onto the locking grooves, it creates a strong, permanent connection that helps resist vibration and maintain structural integrity.

The flush head lockbolt has a head that is nearly level with the surface of the material, providing a smooth finish that reduces aerodynamic drag. Meanwhile, the protruding head lockbolt is designed with a more pronounced head, which can provide a greater surface area for torque application and is often easier to handle during installation.

Both designs effectively utilize the swaged collar to ensure a secure locking mechanism. This swaging process is essential regardless of the specific design type employed, which is why both flush and protruding head lockbolts can feature this characteristic.