Keys – The key element in the world of locks and padlocks

omr bunch of keys various types

The first major division in human history, which shaped culture and arts, was between “nomadic” and “sedentary” people. Digging into the origins of modern locks and padlocks, this distinction already becomes clear.

The first “lock” most likely consisted of a wicker slot fixed on the leaf which, in close position, would match with another wicker slot installed on the frame. A wooden pin would pass through both slots, thus preventing the door from opening… A tool was then needed, whose teeth would on the one hand match the holes where the wooden pegs were inserted and, on the other hand, they had to be as high as the holes drilled on the latch: once the tool was inserted in a slot of the latch itself, it could lift the wooden pegs and, while staying in place, the disengaged latch could be operated.

Find out more about the history of keys and locks in the book by Mandel Gabriele (1990), La Chiave – Storia e simbologia di chiavi lucchetti e serrature, Bergamo, Lucchetti Editore.

The key is not only a metal element aimed at locking and unlocking locks and padlocks. The key finds its symbolic origins in ancient times. Back in the Ancient Egypt the key’s symbolic value was already undoubtly rooted in memory and tradition. Family crests would often feature a key, a symbol of power, so much so that the phrase “to hand over the keys of the city” indicates submission to the invaders.

The key as a magical symbol

Being the key a very powerful magical symbol, also in magic the key takes on a considerable significance, going well beyond its simple use; for example they were used, together with locks, in love potions: a locked casket would trap the lover’s passion.

The decryption key

Another metaphorical use of the term “key” is linked i.e. with the ability to grasp the true meaning of a text, hence finding “the reading key”, intended as the key to understanding, the interpretation. This is even clearer in encrypted systems, enigmas and secret codes: the decryption key is necessary to read the message.

Clef in music

The clef (literally “key” in French) allows to correctly read the notes written on the stave. It combines the correct note to its position on the stave according to the 2 main clefs adopted: the treble (or G) clef and the bass (or F) clef.

Key(stone) and architecture

The keystone, the foundation in construction and symbol of stability, is the wedge-shaped stone at the apex of an arch or a vault. It is the fundamental element to distribute the weight born by the arch on the two side pillars.

Among the many symbols and topics connected to keys, surely security retains its weight and importance. Keys and locks have always secured our goods, apartments, offices and documents.
The house keys are always with us, they are reassuring; so much so that losing them causes distress, anxiety and doubts on the future.
That’s the reason why keys are so important and, just like any other security system, they need to be updated.

Key types

Besides the aforementioned antique keys, there are several key types with diverse features and differences.
Some of them are designed for high-security applications, such as double-bit keys o Euro-profile dimple keys.
As far as the traditional closing systems are concerned, it is possible to draw a distinction between keys according to their features which, also considering the cylinders, make them suitable for specific applications both in terms of security, space and practicality.

Antique key

Chiave antica a leva semplice

The antique key is surely the very first key type we can find in every house. Such key is chiefly used in interior doors, old furniture, vintage objects or wherever a simple low-budget locking mechanism is needed. Therefore, the security level they guarantee is rather low but, at the same time, it is very practical and easy to duplicate.

Budget lock key

Either made of metal or plastic, they feature a triangular, square, double-bit or cross tip (this latter also called FIAT). These types of keys are normally used in water or gas meter boxes, hatches or wherever a high security degree is not requested.

Standard key

Chiave grezza per serrature a lamelle - SCHG05082

Thanks to the technological progress, a new key type was developed, called standard key, which guarantees a higher security level compared to antique keys, while reducing weight and size. Standard keys were used in the recent past on cylinders for front doors. While nowadays for such applications they have given way to high-security locks and keys, they keep being widely used in office furniture. This is the most common key type. The ridges and notches cut on the key shaft, once the key in inserted in the keyway, move pins up and down to align them and allow the rotation that sets the cam into motion.
The alternative to the above-mentioned pin tumbler camlock, is the wafer tumbler camlock: it is operated using the same type of key but, thanks to the wafer’s reduced size, the overall dimension of the lock is smaller. They can then find application in narrow spaces or wherever more discretion (even only aesthetically) is requested. It is widely used in mail boxes, showcases, bulletin boards, hatches, workshop furniture, street furniture, gates automation systems and keylock switches…
The metal key can also operate locks made of alternative materials, such as technopolymer: technopolymer locks are available in a wide range of colours and their features make them suitable for outdoor use and extreme conditions, i.e. the boating industry, where corrosion on metal caused by salt concentration is a major challenge.

Reversible key

Key blank CROSS, A-profile - MCHGYPA

Reversible keys fall within the same category of standard keys but they feature ridges and notches cut simmetrically on both sides of the key shaft, hence the key can be used no matter the direction it is inserted. It is no doubt a practical solution preventing the key from being inserted on the wrong side and from being consequently damaged.
Thanks to its convenience, this key type is widely used in cars and motorbykes.

Tubular key

Chiave tubolare (Plastica e ottone)

The key is a particular cylinder shape and it is used in radial pin tumbler camlocks.
Thanks to the key’s reduced size and the radial pin arrangement, which makes bumping more difficult, they are mainly used in camlocks for removable hard disks or in kensigton cables, gaming or vending machines, cash desks and automatic machines.

Jack key

SCHD05720 - Chiave rossa Jack

It is an alternative to the tubular key and it is particularly safe since it cannot be duplicated as a conventional key in hardware shops. It is also available in the re-programmable version and it is used wherever a high security degree is requested, such as safe boxes, slot machines, vending machines or safes.

Cross key

Chiave a spillo - MCHGYSP

Cross keys are a further development of standard keys. They are easy to duplicate, they guarantee a higher security degree while keeping the same practicality of standard keys. Cross keys can be seen as a mixture between standard and tubular keys since they feature three rows of teeths at 90° on three sides and a flat side which is normally considered the bottom side and that indicates the insertion direction. The peculiar shape of the key and the reduced size of the keyhole make it fit for applications where hiding the keyhole is crucial and other key types are too big.

Keying options

Keys need to have a “map” of the lock in order to be inserted in the barrel, move the pins or wafers and allow the rotation.
Such “map” is called keying, defined as the way a series of keys is matched with a set of locks, so that their locking/unlocking is possible only using the right key.
These are the different keying options available


All keys and locks share the same opening code. This means each and every key can open any lock in the set.


The key is mapped after a specific barrel and it will be allowed to lock/unlock only this specific lock. Through this keying, it is possible to set up more complex systems: for example, out of 10 locks, 3 are keyed alike (hence they can be operated using the same key) and the remaining 7 are keyed different, so one key can operate only one of these locks.


Using the master key, it is possible to open keyed different locks, thus managing access permissions at multiple levels.