How do padlocks work?

Answer 1

There are various forms of padlock each with a different type of locking mechanism. Some are more secure than others but as a rule the two most popular are keyed and combination.

Keyed Padlocks

A padlock that uses a key will have a locking barrel mechanism. In most cases there will be tiny pins located at 90 degrees to the key as it is inserted. The key then has between 3 & 6 groves cut into it and as it is inserted into the barrel it lifts the pins into alignment. Once aligned the barrel can then rotate which causes a horizontal spring loaded bar to shorted. This is often what causes a padlock to spring the key back into its original position if released.

Diagram: http://www.nothingbutpadlocks.com/images/locks/padlock_diagram.gif

The horizontal bars lock into the loop of the padlock. This is known as the shackle and is usually made from a special type of hardened steel. Once released the shackle will spring open.

Combination Padlocks

A combination padlock uses number dials rather than a key and does not have a barrel mechanism. They are usually designed with a series of ball bearings that are aligned when the correct combination is used. The mechanism does not allow the same type of strength you would get in a keyed padlock and so are generally considered a less secure option. Combination padlocks also tend to be less reliable when used outdoors or when exposed to dirt, grit and sand.

Additional sources of information

Overview of padlocks

http://en.wikipedia.org/wiki/Padlock

In-depth padlock information

http://www.nothingbutpadlocks.com/advice

Answer 2

A key lock works by putting a key in and when you turn the key it pushes a loose round piece which releases the lock.