: if all door locks are different and different keys open different locks, how does a universal key work?

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: if all door locks are different and different keys open different locks, how does a universal key work?

In: Engineering

9 Answers

Anonymous 0 Comments

Instead of a single pin in each section of the barrel there are multiple pieces to each pin which makes different keys work in the same lock

Anonymous 0 Comments

A standard lock has pins with different lengths that correspond with the lengths of the notches/ridges on the key. When the right key is inserted, the pins are aligned and the lock can rotate freely.

With a master key, the pins in the lock are segmented so that they can align with two different lengths of notches/ridges. Locks that share a master key all have the same lengths for the first segment but different lengths for the second segment.

Anonymous 0 Comments

The lock opens because the “rings” inside align. The way some locks are made is that there are two sets of rings – one unique for each key, and one same for the master key.

Longer answer is, lock is a small cylinder inside large cylinder, and there are “pins” going between them that prevent the inner cylinder from turning. Correct key pushes them out, thus freeing inner cylinder and allowing it to rotate. To enable master key, you just add an additional cylinder, which results in pins having 3 total possible positions – “at rest”, “unique opened” and “master opened”.

Anonymous 0 Comments

This is a question that’s really hard to explain and understand without a visual aid

Here’s a link to a gif that shows how it works
http://ichiya.com/Lock/images/fig/pinCylinderAniFull.gif

Notice how those pins have multiple spots where they can line up. A master key moves the pins into the other position where the whole thing can turn

Anonymous 0 Comments

Probably only for advanced 5 year olds but [this paper explains master keyed lock sytems and how to make a master key when you only have a regular key. I might be odd but I think its a riveting read.](https://www.google.ie/url?sa=t&source=web&rct=j&url=https://eprint.iacr.org/2002/160.pdf&ved=2ahUKEwjTltDx3NDlAhXyunEKHfCBBtoQFjAOegQICRAB&usg=AOvVaw2Yx6L6LmfZaRNh6a5x0QR8)

Anonymous 0 Comments

In a normal lock (no master key), there are multiple pins along the length of the key that are split in two at different positions, corresponding to the ridges on the key.

When the key is inserted, the ridges lift the pins up and all the breaks in the pins line up along the edge of the lock body, allowing it to turn freely.

For a master keyed lock, each pin is split into three pieces, so there can be a continuous line of breaks in two positions (technically more than two, but unnecessary detail). That means two different keys will work in the same lock.

By having one set of splits in the pins in the same position, but the others in different positions, you can make locks that all open with the same master key but have unique regular keys.

Anonymous 0 Comments

Every lock in a set of locks has two sets of buttons inside them. The key presses one set of the buttons to allow you to turn the key and open the lock.

One set of buttons works with the specific key for that lock. The other set works with the master key.

The “universal” key is not universal. It works with a specific set of locks that was purpose made to be part of that same set. As an example, there might be a master key for an apartment building, or a motel. Those locks were all made to fit a specific master key. Different master keys will not work on every lock you encounter in the world, just on the specific locks from that set. In theory any way. There are probably people out there who happen to have identical keys and locks, but there’s no way of knowing which locks, so that doesn’t matter.

Anonymous 0 Comments

As a side question, what are the chances that a random key you have fits a random lock? Is there a chance my door key works on someone else’s door?

Anonymous 0 Comments

It would be made out of water than when put in the lock instantly hardens molding to that lock and allowing you to open it