North Carolina Locksmith Practice Exam 2025 - Free Locksmith Practice Questions and Study Guide

The screw that fastens a slip-on knob to a lock spindle is commonly referred to as the knob screw. This specific type of screw is designed to secure the knob onto the spindle, allowing for smooth rotation and functionality of the lock mechanism. The importance of the knob screw lies in its role in ensuring that the knob remains stable during use and does not detach or come loose over time, which could compromise the security of the lock system.

In contrast, the other terms mentioned refer to different components related to locks. The hub is a component that connects various parts of the lock mechanism but is not specifically for fastening knobs. The edge-bore typically relates to the hole drilled on the edge face of a door for housing a lock, influencing the installation but not the fastening of a knob. Mortise refers to a type of lock that is installed within a pocket cut into the door, separate from the specifics of knob attachment. Understanding these distinctions is key for effective locksmithing and installation practices.