Locksmith glossary
Clear definitions of locks, cylinders, keys, doors, access systems, security and brands.
A closing mechanism independent of the main lock, which drives a solid bolt towards the frame. It can be operated with a key on both sides or only from the inside by means of a knob. It is installed as reinforcement on home doors, storerooms and secondary access points. Its advantage is that it forces two separate systems to be overcome, not just one. In many cases, adding a deadbolt to an existing door improves security more than replacing the complete lock.
A system that blocks opening from outside even with the correct key. On home locks it is normally operated with an interior knob, and it is what is popularly known as putting the deadlock on. Very useful at night or when there is someone inside. However, if the key is left in on the inside and the door has deadlocking, opening from outside becomes quite complicated and often forces the cylinder to be replaced.
A process by which the combination of a cylinder is determined without having the key, from the mechanism itself or from its manufacturing code. It allows a new key to be made when all the existing ones have been lost, without destroying the lock. It is a legitimate and frequent job in professional locksmithing, always with prior proof of ownership. In high-security systems it is considerably more complex, precisely by design.
A system that allows cash or envelopes to be inserted into the interior of the safe without needing to open it, by means of a slot or a rotating drum. It is common in shops, petrol stations and hospitality, where it reduces the risk during the working day. Its design must prevent the extraction of what is deposited from the opening itself, something that low-range models do not always resolve well.
A method that involves damaging the cylinder or the lock to gain access, with the consequent need to replace what is affected. It is resorted to when the non-destructive route has been ruled out, on faulty or blocked locks, and in emergency situations where time is paramount. What distinguishes a professional is that the destruction is controlled and minimal, limited to the cylinder, without ruining the door or the complete mechanism.
A document that reflects the complete breakdown of the intervention: call-out, labour, material installed, taxes and tax details of the company. It is essential to claim from the insurer, to justify the expense before a residents' association and to enforce the guarantee. A job without an invoice leaves the customer without any of those three protections.
It replaces the lens with a camera and an interior screen, offering a sharper image and a wider angle. Some models record when they detect movement or allow you to check who called in your absence. It greatly facilitates identification for people with poor sight or short stature. It is an added layer, never a substitute: the real security of the door still lies in the cylinder, the escutcheon and the frame.
It has perforations of different depths made on the flat surface, not on the edge. That system multiplies the possible combinations and makes both lock picking and unauthorised copying enormously difficult. Most are also reversible, which is appreciated on arriving at night. Changing a serrated-key cylinder for a dimple one is one of the security improvements with the best relationship between cost and result there is.
A German manufacturer of locking systems, founded in 1936 and with headquarters in Brühl. It is specialised in high-security cylinders, master-keyed systems and electronic access control. Its patented profiles with a restricted key are one of its hallmarks, which allows strict control of copies. It is a common brand in key hierarchies for communities, hotels and office buildings.
View the DOM pageA hydraulic or mechanical device that returns the door to its closed position in a controlled way after opening it. It is common in communal entrances, offices, garages and fire doors, where its installation is usually compulsory. In addition to convenience, it provides security: it guarantees that the door is effectively closed and not left ajar. Its adjustment allows the closing speed and the final latching to be regulated, something that it is best to check periodically.
The audio-only version of the previous one, with a street panel, handsets and a door release. It is still the most widespread system in residential buildings. Its most frequent fault is not in the handset but in the electric strike plate of the communal entrance, which wears out with continuous use and ends up not releasing the bolt even though everything else works correctly.
A generic name for all the metal elements fitted on a door: hinges, handles, escutcheons, strike plates, pulls and bolts. In a quote it usually appears as a combined item, so it is best to ask for the breakdown. Its quality matters more than it seems: flimsy hardware on a security door is the equivalent of a good lock with loose screws, and it is usually the first thing to fail.
It is the moving part of the door, the one that turns on the hinges and houses the lock. Its material, thickness and condition directly determine the security of the whole. A hollow or chipboard leaf offers very little resistance however good the cylinder it fits. Over time it tends to drop under its own weight, which is detected when it rubs the floor or it is hard to engage the bolt: there an adjustment is advisable before it forces the lock.
The element that generates the opening and closing movement, sized according to the weight and the type of door. There are articulated-arm, chain, central-shaft and buried models, each suited to a configuration. It is a frequent mistake to choose it only by price: an under-sized motor always works at the limit, overheats and ends up failing just when it is most needed, normally in the height of summer.
A situation in which the door is held only by the latch, without turns of the key, normally through carelessness when leaving. It is the most favourable case for a non-destructive opening and is usually resolved in a few minutes without damaging the lock. It is not always immediate: very tight seals, out-of-square frames or latches with an anti-crowbar bolt complicate the work, although the least invasive route is sought equally.
An automatic closing system simpler than the door closer, based on a spring that returns the leaf to its position. It can be housed in the floor or surface-mounted. As it lacks hydraulic regulation, the door slams shut, which in the long run punishes both the lock and the frame. On intensively used access points it usually pays off to replace it with an adjustable door closer.
An optical piece installed in the leaf of the door that allows you to see who is on the other side without opening. It has a wide-angle lens that widens the field of vision. It is a basic and very cheap securitand theement, but it is best to choose models with an interior shutter: without it, a conventional viewer can be used from outside with an optical tool to observe the interior of the home.
A Spanish brand specialising in electric door releases and electromechanical strike plates, with headquarters in the Basque Country. Its characteristic product is precisely the element that releases the bolt when the door entry system is operated. It is one of the most widespread references on home communal entrances in Spain, so that when the bell rings but the door does not open, the piece to be replaced is frequently of this brand.
View the DORCAS pageIt allows opening from outside even when there is a key inserted on the inside, thanks to a mechanism that disconnects both sides. It resolves a very annoying everyday situation and also a real security problem: in an emergency, someone can gain access from outside without depending on whoever is inside. It is especially advisable in homes where an elderly person lives alone, or in any household where the key is usually left in.
It has serration on both edges, so that it can be inserted in either of the two positions. It combines the convenience of the reversible key with a number of combinations higher than that of the simple serrated one, since both sides take part in the coding. It is found in mid-range locks and in many aluminium doors. Its level of protection lies between the conventional serrated key and the dimple key.
A destructive method that perforates the cylinder to destroy the pins and the shear line. It requires no skill, only a power tool, although it generates noise and leaves an obvious trace. Anti-drill cylinders incorporate inserts of hardened steel or carbide that spin freely against the bit instead of letting themselves be perforated. Combined with a protective escutcheon, they force the attacker to invest time and to make themselves noticed, which is usually enough to make them give up.
It is a synonym for counter-pin, and both terms are used interchangeably in the sector. The variant driver pin comes from English and appears more frequently in data sheets and manufacturers' catalogues, while counter-pin is the traditional form in the Spanish workshop. There is no technical difference at all between one and the other. If both appear in the same product description, they refer to the same component.
A leaf that has lost its original position due to the wear of the hinges or its own weight, so that it rubs the floor or does not fit in the frame. It is a progressive and perfectly detectable fault: it becomes harder and harder to turn the key. Each forced closure punishes the lock, so readjusting the hinges in time avoids a considerably more expensive fault.
A system that requires two different keys, held by different people, in order to open. It is used in environments where no individual should have access alone: pharmacies, banking entities, deposits of valuables or the custody of sensitive documentation. It is a measure of internal control rather than resistance against theft, and its effectiveness depends on the two keys really being kept separately.
Equipment that manufactures a new key by following the contour of an original by means of a tracer and a cutter that work in parallel. It is the basic machine of any locksmith's. Its precision depends on the adjustment and the condition of the cutter: a poorly calibrated duplicator produces copies that enter but force the cylinder, accelerating its wear without the user knowing why.