XD SERIES wheel center cap screws are generally considered to be the best screws for holding components firmly in place, as they provide a greater amount of torque than other types of screws. Additionally, Allen screws are extremely easy to use, as they fit with a hex key or Allen wrench. Additionally, Allen screws are less prone to "cam-out" than other types of screws, meaning they are less likely to slip out of the slot while tightening them. Therefore, Allen screws are generally considered to be the best choice for most applications.