Selecting a lock
Factors to consider when choosing industrial locks and locking systems
Flat key versus radial or tubular key
There are many lock designs in general use; some use flat keys of various types and others use tubular keys. Numerous variants of each are available from different manufacturers. The overall level of security available from each of these types of lock is defined by five main factors.
- The number of effective key codes (or ‘key differs’) the lock offers.
- The physical strength of the lock, ie. its resistance to outright attacks using tools.
- Its resistance to picking or other forms of manipulation.
- The ease (or otherwise) with which it is possible to obtain keys, both legitimately and also from unauthorized sources.
- Whether you need many of the locks to be keyed alike. Some mechanisms are more easily incorporated into a wide variety of locks, enabling one key to open locks of many types within a set (or ‘suite’).
Before selecting a lock it is advisable to have considered four main aspects.
- Security level required
First, face facts: security costs money. A good lock acts as a strong deterrent, giving protection by being difficult and time-consuming to penetrate. It is important to assess risk. For instance, in industrial applications, very often a lock has only to be tamper proof, so it is unnecessary to choose the most complex device; it is likely that price, ease of fitting and simplicity of use are more important than outright security. Conversely, you may wish to protect a truly valuable item in an unsupervised location, so a lock able to withstand a sustained assault would be more appropriate, causing a criminal to take a long time to attempt entry and be in greater danger of being caught in the act.
- Mechanical security and vandal resistance
Some locks are required to be fitted to a product that will be attack tested for accreditation to a certain standard, information that needs to be passed to us at the beginning of an enquiry. Very often, the way in which a lock is fitted can be of as much help in preventing forced entry as the inherent strength of the lock itself. Correct installation is essential to reinforce the lock’s own integral strength. When physical assault is expected, special care is needed to disperse much of the loading into the mountings and away from the lock itself. For example a ‘screw type’ lock or handle may well be stronger than the equivalent cam type in certain applications. Additional accessories such as protective collars, reinforcement sleeves and backing nuts are available to substantially increase the operational strength of the lock.
- Types and dimensions
The type of lock required is invariably affected by the type of closure (hinged door, sliding door, lid, etc) the space available and the loads expected to be imposed on it. In industrial applications, the most commonly used are cam locks where the key rotates a cam or pawl, to engage behind a keep or door frame, or T-Handle assemblies for securing larger, heavier doors perhaps involving air-tight seals or multi-point locking. ‘Screw’ or stud type locks or handles save space because they provide a very tight and secure fit and do not require space for the swing of a cam. Other options include switchlocks, pushlocks, padlocks, and specially designed products for certain types of business or application. Key rotation and withdrawal are also a consideration here, particularly when dealing with cam locks. Many have the option of 90° or 180° rotation, left or right, and a choice of whether or not the key may be removed in its open position. Please note that all imperial dimensions provided on this website are an approximate conversion of the metric equivalent and should not be precisely relied upon when selecting products. Accurate imperial dimensions for any product can be supplied upon request.
- Key configuration
Basically, there are four options available:
- Keyed alike
All locks in a set or ‘suite’ have the same key code, ie. any key fits any lock. This is convenient where a large number of locks are to be used by the same people but can be a problem in the event of loss or theft of a key, possibly giving unauthorised access to all locks within the set. This shortcoming may be avoided by specifying reprogrammable locks that allow the combination to be changed in situ to restore maximum security within seconds.
- Keyed to differ
All locks have different key combinations, ie. a key from one lock will not fit any other lock in the same group. Note: there is usually a limit to the total number of differs available for a particular lock group. Lower cost locks with fewer combinations available may be supplied with duplicated key numbers and not be truly keyed to differ.
- Master keyed
As used in hotels where one ‘master’ key can open all the locks in a suite, which are themselves made to different key combinations.
Changeable combination locks, also known as Camatic, Multi-code, U-Change or Varicode locks. A lock design offering several independent and interchangeable key combinations and two types of key, an ‘Operating’ type to open the lock and a ‘Change’ key for reprogramming. By inserting the Change key, the key code of the lock can be altered quickly and easily. This avoids the need to replace many ‘keyed alike’ locks if a key is lost or stolen or the lock code is compromised. Often used where a high turnover of staff is an issue.