Locksmith glossary
Clear definitions of locks, cylinders, keys, doors, access systems, security and brands.
The amount corresponding to the technician's work, independent of the material used. It varies according to the complexity and the duration of the intervention: a fine opening on an armoured door requires considerably more time and skill than a door slammed shut. It must appear broken down on the invoice, separate from the material, so that the customer knows exactly what they are paying for.
A door of large dimensions intended for the passage of vehicles, common in garages, industrial units and access points to properties. It can be hinged, sliding, up-and-over or sectional. Its weight requires the hardware and the anchors to be looked after especially, and on communal access points its blockage leaves many users without a way out at once, which is why it is usually treated as an urgent incident.
A piece with a bevelled end that protrudes from the lock and retracts on its own on hitting the frame, allowing the door to close with a simple push. It is what keeps a communal entrance closed without needing to turn the key. It differs from the bolt in that the latter has a straight end and only moves with the key. A latch that does not retract well usually indicates accumulated dirt or a fatigued internal spring.
A specific variant of the previous one, aimed at retracting the latch from outside without operating the lock. It is the same as what is popularly known as the card technique. It is only viable with the door slammed shut and with no protection on the latch. The solution is twofold and very simple: always turn the key when leaving and install a latch with an anti-crowbar bolt, which is blocked automatically when closing.
It is the one that closes on its own when the door is pushed, without needing to turn the key, thanks to a latch with a bevelled edge that retracts on hitting the strike plate. It is the mechanism of communal entrances and of most home doors. Its convenience has a well-known downside: a moment's carelessness is enough to get locked out with the keys inside, the most frequent incident in any door opening service.
A bolt installed on one side of the door, usually on the side opposite the factory lock, that anchors it to the frame or the floor. It is a very effective reinforcement on up-and-over garage doors and on metal closures, precisely because it forces two separate points to be overcome. Its installation is simple and of reduced cost, and it quite improves the resistance to levering.
A small, simple mechanism, normally a cam or latch type, that secures the little door of the letterbox. It is usually of low complexity, since its function is to deter rather than to resist. The key is lost very frequently, precisely because of its size. When this happens, the opening is simple and afterwards the cylinder is replaced to provide new keys; on communal letterboxes it is advisable to notify the property administrator first.
An internal metal plate, mounted on a spring, that must reach an exact height to release the bolt. It is the characteristic element of locks that work with a bit key, and that is where that type of lock takes its name from. The more levers, the more possible combinations. Over time they lose tension and the key starts to need a knack to turn, a clear symptom that the mechanism is approaching the end of its service life.
A horizontal lever that operates the latch when lowered, allowing the door to be opened without a key. It is the most widespread system in Europe and also the most practical for people with reduced mobility, since it can be operated with the elbow or the forearm. When it stays down or does not recover its position, the fault is usually in the return spring of the lock, not in the handle itself.
An attack that applies force by means of a lever in the gap between the door and the frame, seeking to overcome the closing points or deform the leaf. It is more frequent on wooden doors with a weak frame and a thin-plate strike plate. The effective defences are structural: perimeter bolt pins, a strike plate anchored to the structure, anti-crowbar hinges and a frame in good condition. An excellent cylinder is of little use if the door gives way at the edge.
A key intended for lever locks, those of old mechanism with internal plates mounted on springs. Its function is to raise each lever to the exact height that releases the bolt. It is recognised by its considerable size and its classic appearance. It is still found in old homes and interior doors. Its main disadvantage is not only the limited protection, but the growing difficulty of obtaining quality spare parts and duplicates.
An old system that works with a bit key, that large key of classic appearance. Instead of pins, it has internal plates called levers that the key must raise to the correct height to release the bolt. It is still found in old homes and interior doors. Its level of protection against current techniques is limited and finding spare parts is increasingly difficult, so it is usually recommended to modernise it while keeping the original fittings if they have aesthetic value.
A type of hinge formed by two separable pieces that are assembled by means of a vertical pivot, much used on passage doors and traditional joinery. It allows the leaf to be removed simply by lifting it, which is convenient for maintenance but constitutes a clear weakness if installed on an exterior door without additional protection. On home access points it must always be combined with fixed bolt pins or anti-crowbar hinges.
An element that tells the control unit at what point the door must stop when opening and when closing. It can be mechanical or electronic. Its misadjustment produces very recognisable faults: the door does not close fully, hits the floor or leaves a gap when opening. It is a simple door repair if attended to soon, before the stops end up damaging the structure.
A Spanish manufacturer with headquarters in Alicante, specialising in locks, deadbolts, padlocks and security systems for homes and shops. It is one of the most widespread brands in the national market, with a notable presence in rim deadbolts and high-security locks. Being an Alicante manufacturer, the availability of spare parts throughout the province and in the Vega Baja is very good, which speeds up any replacement.
View the LINCE pageMechanism that fixes a door to its frame and prevents it from being opened without the key or the corresponding operating system. It includes the complete assembly: the case that houses the mechanism, the bolts that come out towards the strike plate and the cylinder that receives the key. It is commonly confused with the cylinder, but they are different things: the cylinder is only one part of the lock, and in many faults it is enough to replace that part without touching the rest of the assembly.
A technical examination of a lock to determine whether it was manipulated, forced or opened with a key, and in what way. Its result is set out in a report that may have value before the insurer or in judicial proceedings. It is decisive after a theft without obvious signs of force, a situation in which many companies question the cover. For it to be valid, the lock must be kept unmanipulated after the incident.
It is the metal body that contains the internal mechanism: the springs, the cams and the parts that move the bolts and latch. In a mortice lock it is hidden inside the edge of the door and only its faceplate can be seen. When the fault is here and not in the cylinder, the key turns but the door does not open, or the bolts do not come out fully. In that case it is no longer enough to change the cylinder.
Replacement of the complete mechanism, not just the cylinder. It becomes necessary when the fault is in the case, the bolts or the multi-point bar, or when the lock has been left useless after a forcing. It is more laborious and costly than a cylinder change, so it is best to confirm first where the fault really lies: in many cases that seem serious, it is enough to replace the cylinder.
Replacement of the lock in the framework of a judicial eviction procedure, carried out on the appointed date and in the presence of the judicial commission or the designated agents. It requires the ruling that supports it, with no exceptions or urgencies that count. The owner who has a procedure under way must coordinate the action with their lawyer or court representative, providing the documentation in advance.
The popular name for the cylinder, and the one used by practically everyone. It is the piece into which the key is inserted and, in most homes, the most attacked point of the door, since it is usually the weakest link of the assembly. A cylinder change is a fast and modest-cost intervention that allows several levels of protection to be gained without touching the door or the lock, provided the right size is chosen.
It is the long metal plate visible on the edge of the door, crossed by the holes through which the latch and the bolts emerge. It is screwed to the leaf and holds the lock case in its housing. In addition to a structural function, it acts as reinforcement against levering. If it appears bent, scratched or with loose screws, it is worth checking it: it is usually the first visible sign of an attempted forcing.
A product specific to the maintenance of the mechanism, available in powdered graphite form or in dry aerosols formulated for locksmithing. Its function is to reduce friction without leaving a sticky residue. The most widespread mistake is to resort to household oil or the multi-purpose lubricant from the garage: they relieve for a few days and then trap dust and sand, something especially damaging in homes near the sea such as those of La Mata or Aguamarina.
The action of manipulating a lock with a pick until achieving its opening. Carried out by a professional, it allows entry into the home without any damage; used for criminal purposes, it is a silent method that leaves hardly any visible trace. The effective defence is the same: cylinders with mushroom or spool pins, complex internal channels and a protected key profile. A basic-range cylinder with five ordinary pins offers very little resistance to this technique.
Deliberate damage to the mechanism, usually by inserting glue, matchsticks or objects into the keyhole to prevent the use of the door. It is more frequent than it seems in communal entrances and premises. It is best not to insert the key or apply solvents on your own, because the damage is aggravated. A professional extracts the material and assesses whether the cylinder can be cleaned or must be replaced.
A professional dedicated to the installation, repair and opening of locks, doors and security systems. Their work combines mechanical knowledge, specific tools and judgement to decide when to repair and when to replace. A serious professional identifies themselves, gives a quote before intervening and issues an invoice. They must also ask for proof of ownership before opening any home: a locksmith who does not do so is not an advantage, it is a risk.
A manual tool with an abrasive surface used to reduce, adjust and refine metal pieces with precision. It is still essential despite all the machinery available: adjusting a lock faceplate, touching up a strike plate or correcting the cut of a key are jobs resolved by hand. There are different profiles (flat, round, triangular, half-round) according to the zone to be worked.
The trade and activity that ranges from door opening and lock changes to the manufacture and assembly of metal elements such as grilles, railings and closures. It also designates the establishment where it is carried out. Traditionally it included forging; today it has specialised towards security, although many workshops still combine both facets, especially in areas where exterior metalwork still has demand.
A specific bit, generally of cobalt or tungsten carbide, capable of perforating the hardened steels that security cylinders incorporate. It is used in controlled destructive openings, when no other route remains. It is also the tool against which anti-drill protections are designed: the hardened inserts of the cylinder are intended precisely to wear down the bit instead of letting themselves be perforated, prolonging the attempt until it becomes unviable.
A small-diameter camera, mounted on a flexible cable, that allows the inside of a lock or a closed mechanism to be seen without dismantling it. It is used in the diagnosis of complex faults, in safes and in multi-point locks where the fault is not visible from outside. Its main use is to avoid unnecessary destructive openings: seeing what has given way inside allows the specific part to be repaired instead of replacing the whole assembly.
A document that sets out the examination of the lock, the evidence found and the technical conclusions about how the access occurred. It is decisive after a theft without obvious signs of force, a situation in which many companies question the cover. It must include methodology, photographs and the identification of the expert, and it is best to request it before repairing or replacing anything.
A portable set that brings together the tools needed to resolve a complete intervention away from the workshop: picks, tension wrenches, extractors, bits, screwdrivers, caliper and usual replacement material. Its preparation makes the difference in an emergency service, since a technician who arrives without the right material forces a second visit, with the annoyance and added cost that entails.
A lock that incorporates its own acoustic system, triggered on detecting manipulation, vibration or an attempted forced opening. It is a compact solution for storeroom, garage or secondary-access doors where it does not pay off to install a complete alarm. Its effectiveness is deterrent: the unexpected noise is usually enough for whoever forces a door to abandon and leave.
A method that consists of inserting a flexible sheet between the leaf and the frame to push the latch and release the door. It only works when the door is slammed shut, without turns of the key, and when the latch lacks protection. Prevention is simple and costs nothing: always turn the key when leaving. Installing a latch with an anti-crowbar bolt or a security strike plate closes this route definitively.