What is the end of a handcuff key that is the key end/flag called?

• A. Double lock activator
• B. Key end/flag
• C. Teeth edge
• D. Pivot end

Answer: (B)

The end used to operate the lock is called the key end, or flag. This part is the portion you grip and insert into the lock to turn and release the cuffs. It’s defined by its role in manipulating the mechanism, not by any serrated edge or other feature. A separate feature on some cuffs is the double lock activator, which serves to engage a second locking mode and is not the part used to turn the lock. The term “flag” specifically describes that turning end, distinguishing it from other components, like the actuating piece or a serrated edge that wouldn’t serve as the main turning end.