HOW STUFF WORKS
QUIZZES

The Ultimate Combination Locks Quiz
by Staff
Combination locks -- the keyless lock on your gym locker or the more complex ones found on safes -- are a very effective way of securing your belongings without the risk of losing a key. You turn the dial this way and that way, and eventually the lock opens. Wouldn't you like to know what's happening inside the lock? Take this quiz to learn more about how combination locks work.

• 100 years
• 300 years
• 500 years

### The combination dial is which part of the lock mechanism?

• The dial with the numbers on it is the combination dial.
• The combination dial is the set of gears inside the lock.
• The thin metal pin that turns all of the gears is the combination dial.

### Which of these statements best defines a wheel pack?

• A wheel pack is the latch that locks the door of a safe.
• A wheel pack is a set of gears that make up the opening mechanism of a combination lock.
• A wheel pack is a set of four locks sold at a discount price.

### The combination dial is attached to which of these?

• the drive cam
• the wheel fly
• the spindle

### What determines how many wheels there will be in a wheel pack?

• There will be as many gears in the wheel pack as there are numbers in the combination.
• A combination lock always has five wheels in the pack.
• Every manufacturer uses a different number of wheels in their wheel packs.

• fence
• drive pin
• wheel notch

• drive pin
• fence
• wheel fly

### Each wheel has a small gap in its perimeter known as what?

• a gear gap
• a wheel notch
• a lock slit