Keys for homes are typically made of brass or nickel and have a pin tumbler type mechanism giving around 65,000 combinations for a given type. House keys can have different shaped groves down the sides, known as the key broaching. This broaching restricts the insertion of a keys into a lock to only it s matching type, adding to the security by giving more variables to the key. Generally house keys can be readily duplicated (copied) at a locksmith or hardware outlet.

Are used in mortise locks, and were common place in homes built prior to the 1950s. The keys were made of steel or an aluminium alloy and had a shaft of around 5 to 6 cm. These keys generally afforded little security having only two levers with only three different gates giving only a few combinations, with the most common type only having six key combinations. It was well known that should you have lost the key to your home you could borrow a key from a neighbour up the street that would be the same key as yours. Companies like Yale , Chubb , Union , and Legge also made a high security range having typically 5 levers with up to 6 gate positions. This gave hundreds and in some cases thousands of key combinations. These locks had much tighter tolerances in their construction, and were extremely difficult to manipulate. They also often had hardened steel protecting the vital area of the lock. These keys were hand finished with a file by a locksmith using a gauge to ensure an exact copy.

A high security key is typically a key having a patented mechanism or method of creating unique properties, allowing many key types, often hundreds of millions of combination varieties. High security keys are highly sophisticated requiring high tech machinery to cut the keys. High security keys can generally only be cut by the original manufacturer or a locksmith having a contract or licence arrangement with the manufacturer.

Restricted keys are designed to only have keys cut by authorisation of the owner. This is generally done by a signature identification. Restricted keys are generally of a high security nature, but may also be a standard type pin tumbler mechanism having the broaching (shape of the grooves on the key) or other feature protected by registered design & or patent. A restricted key is used to ensure key control ie. unauthorised key copying is not possible.

These keys are found in most modern cars. The electronic chips come in many types & levels of sophistication. Car manufacturers use several different systems with key duplication both inconvenient and expensive, with keys sometimes costing over $2500.00 each. Larger Locksmith businesses, can cut most of these electronic keys as well as program the electronic heads. Some types can only be programmed by the dealer with a locksmith still needed to cut the physical key. A locksmith is the best option to try in the first instance as a substantial cost saving can be made, over using a car dealer.