Unlock Your Potential: Master the 2026 North Carolina Locksmith Challenge!

The part of a cylinder that contains the keyway and tumbler chambers is the plug. The plug is a crucial component of a lock cylinder, where the key is inserted. When the correct key is used, it aligns the pins within the tumbler chambers, allowing the plug to turn and thus operating the lock.

Understanding the role of the plug is fundamental for locksmithing as it directly relates to the mechanics of how locks function. The other options do not contain the keyway and tumbler chambers:

- The lockset refers to the entire assembly of the locking mechanism, which includes the lock, knobs, and other hardware, but is not specific to the area where the keyway and tumbler chambers reside.

- The lazy cam is a type of mechanism that can assist in the locking and unlocking process but does not hold the keyway or tumbler chambers.

- The latch bolt is a part of the locking mechanism but specifically serves to secure the door in a closed position, not to house the keyway and tumbler chambers.

Therefore, the plug's role as the part containing the keyway and tumbler chambers is essential to understanding lock mechanics.