North Carolina Locksmith Practice Exam

Which type of progression uses key bittings based on two columns of the key bitting array?

1. Two Column Progression

2. Three Column Progression

3. Active Retainer

4. Two Step Progression

The correct answer is: Two Column Progression

The type of progression that utilizes key bittings based on two columns of the key bitting array is known as Two Column Progression. This system is designed in a way that it organizes key bitting patterns into two distinct columns, which can enhance the diversity of key combinations available within a lock system. By employing two columns, locksmiths can effectively create a broader range of key variations, making it easier to establish unique keys that do not easily duplicate previous combinations. This allows for better security as well as user-friendly access control measures since different keys can be made to only fit specific locks in a given set. While other progression systems like Three Column Progression use additional columns to maximize key variations or other methods like Two Step Progression and Active Retainer serve different specific purposes in lock design and function, they do not apply this particular two-column bitting method. Understanding the structure and implications of the two-column approach is essential for locksmiths looking to optimize their key systems for both security and functionality.