Locksmith glossary
Clear definitions of locks, cylinders, keys, doors, access systems, security and brands.
An element that reveals that someone has tried to act on the lock, by means of a visible indicator, a change of colour or a record in electronic systems. It is especially valuable against techniques that leave hardly any trace, such as bumping. Knowing that there has been a previous attempt allows the door to be reinforced before it is repeated, instead of discovering it when the entry has already been consummated.
An access code with validity limited to a period or to a specific number of uses, after which it automatically stops working. It is the ideal solution for holiday rentals, cleaning staff or maintenance technicians. It avoids the classic problem of keys that never come back. In holiday homes in Playa Flamenca and Villamartín it has become the most practical system for managing arrivals and departures without a physical presence.
It is another name for the tension wrench, very widespread in catalogues and translations from English. It is not a key in the strict sense, since it carries no coding and operates nothing on its own: it merely transmits the turning force. The confusion is frequent among those who approach the vocabulary of the trade for the first time, and it is worth clarifying because it has no relation whatsoever with the keys of a home.
An L-shaped piece that is inserted into the keyway to apply slight turning pressure while the pins are manipulated. Without that tension, no manipulation technique works, since the pieces would return to their position. It is the essential complementary tool in any fine opening. Its existence explains why security cylinders incorporate mechanisms that detect and penalise incorrectly applied tension.
A Spanish manufacturer founded in 1941, with headquarters in Guipúzcoa, part for years of an international security group. It is probably the best-known locksmithing brand in Spain, with cylinders, mortice and rim locks, electronic locks and access control for hotels. Its enormous presence in the housing stock makes it one of the brands with the easiest spare parts to obtain.
View the TESA pageThe lower horizontal piece of the frame, located at floor level beneath the door. It fulfils sealing and finishing functions, and on exterior access points it incorporates systems to drain the water. In homes near the sea it is an exposed zone: sand and humidity accumulate there and accelerate the corrosion of the lower fittings. Cleaning it regularly prevents the door from ending up rubbing or the lower bolts from seizing.
A cylinder that replaces the keyhole at one of its ends with a rotating knob, so that from that side it opens without a key. It is usually installed facing the inside of the home, so as not to depend on the key while inside, and it is also the typical solution on garage and storeroom doors. It has an important precaution: it is not advisable to fit it on doors with glass or nearby openings, because the knob would be accessible from outside.
A spring housed in the shaft that counterbalances the weight of the door or the shutter, allowing it to go up with little effort. It is the element that makes it possible to manually move a leaf of hundreds of kilos. It works under considerable tension, so its adjustment and replacement must be left to a professional. If you notice that the door has suddenly become heavy, it is almost always a fatigued or broken spring.
A locksmithing brand present in the Spanish market, with a catalogue of locks and closing elements for homes and joinery. It appears in domestic installations and in professional distribution alongside the main national manufacturers. As with other standardised-format brands, its euro-profile cylinders can be replaced with others of a higher security grade without needing to change the lock.
View the TOVER pageA part of the duplicator that runs along the profile of the original key transmitting its shape to the cutter that cuts the copy. Its condition directly conditions the fidelity of the duplicate. A worn tracer rounds the cuts and produces imprecise keys, which work at first and end up giving problems. It is one of the least-known causes of a new copy starting to fail soon.
It incorporates a passive electronic chip housed in the head, which responds to the signal emitted by the vehicle. Without that correct response, the engine does not start even if the key turns mechanically in the cylinder. It is the basis of the anti-theft immobiliser fitted by cars since the late nineties. That is why a car key copy requires two different operations: cutting the metal part and programming the chip.
A key of triangular section, without cuts, used to operate service locks on garage doors, technical panels, lifts and installation cabinets. It is a universal key, not a security one: its function is to give access to authorised staff, not to prevent passage. Precisely for that reason the protection of an access point should not be entrusted to it, although it is very practical for manual release.
A key with a hollow body and circular section, with the cuts distributed around the edge. It is used in vending machines, lockers, metal furniture and some padlocks, almost never on home doors. Its peculiar shape makes it easy to recognise. The old models had a reputation for being vulnerable, although manufacturers have corrected much of those weaknesses; in any case, it is not the right system for a home access point.
Its mechanism is housed in a cylinder of circular section and works with a tubular key, hollow and rounded, whose cuts are distributed around it. It is found above all in vending machines, lockers, furniture and some padlocks. In the domestic sphere it is uncommon. The old models offered scant protection, although current manufacturers have incorporated notable improvements; in any case, it is not the right option for an entrance door.
A Spanish manufacturer of locks and cylinders with a long history, currently part of the DOM group together with MCM. Its catalogue covers mortice locks, rim locks and euro-profile cylinders, with a wide presence in the Spanish residential stock. Its membership of an international group makes it easy to keep spare parts available and to integrate its products into wider master-keyed systems.
View the UCEM pageA European standard that establishes the requirements and burglary-resistance tests of safes, cash machines and strongrooms. It classifies the products into grades according to the time and the tools needed to overcome them, both for partial and total access. It is the reference that allows models to be compared with an objective criterion and the one used by insurers to set the limits of cover for the contents.
A European standard that establishes the criteria for the classification and testing of lock cylinders, evaluating aspects such as durability, attack resistance and the number of combinations. It is the reference that allows cylinders from different manufacturers to be compared on a common basis. If a cylinder does not indicate its classification in accordance with this standard, there is no objective way to know what protection it offers beyond what the packaging promises.
A European standard that classifies and establishes the tests of mechanical locks and their strike plates, evaluating durability, load resistance, security and corrosion. It is the reference equivalent to UNE-EN 1303, but applied to the lock and not to the cylinder. It is worth bearing in mind when comparing products: a lock and a cylinder are certified separately, so an excellent cylinder may be fitted in a mediocre lock.
A garage door formed by a rigid leaf that turns on itself until it lies horizontal beneath the ceiling. It is the traditional solution in individual garages. Its known weak point is the resistance to levering at the ends, where the leaf gives way relatively easily. Reinforcing it with lateral deadbolts on the side opposite the factory lock notably improves its security.
A rigid single-piece leaf that turns on itself until it lies horizontal beneath the ceiling. It is the traditional solution in individual garages. Its known weakness is at the ends, where the leaf gives way to levering relatively easily. Reinforcing it with lateral deadbolts on the side opposite the factory lock improves its security quite a lot, and it is a simple and economical intervention.
Intentional damage to access elements without the aim of theft: sabotaged locks, scratched closures, torn-off remotes or smashed bells. It affects above all communal entrances, premises and communal areas of urbanisations. Against it, escutcheons with a sliding cover, protected locks and lighting of the access work well, simple measures that greatly reduce the exposure of the most punished point.
A system that combines audio and image to identify whoever is calling before opening. It consists of an exterior panel with a camera and microphone, and of monitors in the homes. It is common in communities and detached houses. It is best to distinguish its faults: if the problem is the image or the sound, it corresponds to a telecommunications installer; if the door does not open despite the bell ringing, the fault is usually in the electric lock.
Access made by going through a wall, a ceiling or a slab, instead of forcing the door. It is a modality associated with commercial premises, entities and warehouses with party walls. Against it, reinforcing the door is of little use: what works is vibration sensors on the surfaces, volumetric detection inside and anchors that prevent moving what is to be stolen.
An internal obstacle in the lock that prevents the passage of any key whose profile does not exactly match the intended one. It acts as a first mechanical filter even before levers or pins come into play. In old locks they are the parts that force the key to have those characteristic cut-outs on the bit. Its function is one of selection, not resistance: a ward prevents a wrong key from entering, but it does not stop a deliberate attack.
A workshop term that designates the progressive wear of a lock or a key through continued use, until the mechanism loses precision. A worn key has rounded cuts and no longer aligns the pins well; a worn cylinder allows play where there should be none. It is the explanation of why a lock that worked perfectly starts to need a knack. It is not a sudden fault but a deterioration that warns for months.
A profile of rubber, silicone or brush placed around the perimeter of the door to improve thermal and acoustic insulation and to stop the entry of dust and water. It fulfils its function well, but it has a little-known side effect: a seal that is too thick generates pressure on the leaf and makes it difficult for the bolt to enter cleanly into the strike plate, forcing the door to be pushed each time the key is turned.
A permanent joining of metal pieces by means of the fusion of the material. In locksmithing it is the base technique for manufacturing grilles, railings, gates and reinforcements. The quality of the weld bead determines the resistance of the joint, which is usually the point through which a structure fails. In marine environments it is best to protect the welds well, since they are the zone most prone to starting corrosion if they are left untreated.
A variant in which one of the ends incorporates a knurled wheel instead of a keyhole, allowing it to be opened with the fingers from that side. It fulfils a function similar to that of the thumbturn cylinder, although with a more discreet and less protruding profile. It is installed facing the inside of the home or on storeroom doors. The same precaution as with the knob: it is not advisable on doors with glass or nearby openings that would allow it to be reached from outside.
An electronic lock connected to the domestic network, manageable from the mobile even remotely. It allows opening at a distance, generating temporary codes and checking the access record. It is very practical in holiday rentals. It introduces its own considerations: higher battery consumption, dependence on coverage and the need to protect the associated account well. The mechanical cylinder as a backup is still essential.
A brand of American origin, whose name comes from Linus Yale, the inventor in the mid-19th century of the pin cylinder that is still the basis of most current locks. Today it is part of a large international security group. Its catalogue covers cylinders, locks, padlocks and connected smart locks. It is one of the most recognised brands in the world and its name is sometimes used, improperly, as a synonym for cylinder.
View the YALE pageContinuous availability, without interruption, seven days a week and every day of the year. It does not mean that there is a technician waiting on every street, but that there is an organised shift that guarantees attention at any hour. When you call, an honest professional gives a realistic estimate of the arrival time according to the distance and the moment, instead of promising times impossible to keep.