Glossary of terms in alphabetical order



The measurement used on nightlatches and mortice locks.

Bathroom Lock

A mortice lock which is used with thumbturn handles to allow the occupant of the bathroom to lock the door from the inside.


This British Standard applies to Mortice Locks and Nightlatches.  All locks that carry the BS3621 kitemark meet the standards set by insurance companies and the police.


The British Standard that relates to the overall performance of PVCu windows.

BS6375, Pt 2

The British Standard that relates to the effectiveness of “child safe” restrictor hinges.

BS EN 1935

This standard provides details on product types, classification by use, test cycles, door mass, corrosion resistance, as well as definitions, product performance requirements, test apparatus, test methods and marking of products. In addition, the published standard includes annexes with details for special applications.

CE Marking

CE Marking on a product is a manufacturer's declaration that the product complies with the essential requirements of the relevant European health, safety and environmental protection legislations, in practice by many of the so-called Product Directives.

BS EN 1303

This standard classifies cylinders using a 7 digit coding system.  Each digit refers to a particular feature of the product measured against the standard's performance requirements.  The standard includes tests on durability, fire and corrosion resistance.


The British Standard that relates to the enchanced security of windows.

Butt Hinge (for doors)

Hinges are designed for timber doors, purchased pre assembled and fitted on site to enable doors to be hung

Compression rollers/Mushrooms/Cams

Compression rollers can generally be found on multi-point locks that are installed into PVCu doors. They may be positioned at various intervals along the faceplate of the lock and help to create an even weatherseal down the locking side of the door, thus helping to prevent draughts and water seepage.

Note: Compression rollers are primarily designed to create compression. Should security be priority on the door, Yale recommend multiple locking points be specified  i.e. hookbolts.

Carbon Steel

An alloy which is used in the manufacture of window hardware, usually being coated to increase its corrosion resistance.


British Standards Institute



On a mulit-pojnt lock, the deadbolt is located at the centre of the lock to add increased security. Normally of rectangular shape but can also be in the shape of a hook.


A mortice deadlock does not have a latch, but a bolt only which is operated by key.

Some nightlatches have a deadlocked function that adds extra security to the locking mechanism after the key has been rotated for a second time.

Door Chain

Also called Door Limiter. A fitment that restricts the door to being partially opened in order to identify callers prior to opening the door for access. Can be either an integral part of the lock mechanism or surface mounted on the inner face of the door.

Door Limiter

Also named Door Chain. A fitment that restricts the door to being partially opened in order to identify callers prior to opening the door for access. Can be either an integral part of the lock mechanism or surface mounted on the inner face of the door.

Dummy Mullion

A bar that is fixed onto the side of either a French door/window which secures the door in a locking position.

Electric Strike

An electrical device that permits releasing of the lock in the door from a remote control.


Another term for multi-point locks usually used on windows.

Euro Profile Cylinder

A cylinder barrel with a specific shape that can be fitted and used in many types of locks including mortice locks and multi-point locks.


A 16mm groove located on the inside of an aluminium or PVCu door blade profile extrusion. This is a standard feature on most PVCu and aluminium doors and is generally where a multipoint lock will be located.


The exposed surface of a multi-point or mortice lock which shows in the edge of a door after installation.

Flag Hinge (for doors)

Door Hinge system used on PVCu Doors which allows for easy installation and adjustment.


Also called Rower

A square hole created in the backset of a mortice lock to allow the spindle to feed through to operate the handle.

Fully Reversible Window Hinges/Stays

Typically used on upper floor windows which are difficult to reach. A fully reversible window allows a glazed sash window to rotate nearly full circle within its frame without protruding into the room. When in the reverse position, the outside of the sash can be cleaned from inside the home.



Hook shaped bolts used on a multi-point lock, designed to assist door compression and a high level of security against forced attack


Journal Supported Door Hinge (for doors)

Used on external doors for high-usage situations and gives maximum endurance with minimum maintenance requirements.


A metal plate or box which is pierced or recessed to receive the bolt or latch when projected


A BSI Kitemark is a trusted mark/symbol of product quality recognized by consumers and specifiers. Kitemarked products have passed a rigorous certification process and can be repeatedly manufactured and supplied to the same standard and purpose for which they were designed.

In addition to this, the products and quality management systems of Kitemark licensees are audited periodically to maintain product quality under ISO 9001: 2000

Laminated Glass

A type of “safety glass” much stronger than float glass, made up of two layers of glass bonded together with a tough plastic film.


Most mortice sashlocks have an easily reversible latchbolt for securing the door so that it can still be operated by handle from either side.


Levers are used in some mortice locks and padlocks.  The higher the number of levers a lock contains, the higher the level of security it offers.

Locking Point

The point where the multi-point lock enters the outer frame of the door, using either a hook or a rectangular shaped bar.


Master Key

One key that operates a number of locks where the individual locks each have their own, different key.  For further information, contact your locksmith.

Mortice Lock

The lock fits into a mortice that has been ‘cut out’ of a timber door edge. The locking action is achieved by a bolt that shoots out of the lock into the striker plate when the key is turned.



The vertical member of a sash, window or door frame between openings in a multiple opening frame.

Multi-Point Lock

Describes a type of lock mechanism that has more than one locking point.  It usually has a minimum of three locking points (plus latch) spread strategically over the length of the door.  Multi-point locks are typically used on PVCu or composite doors.


A lock which is mounted onto the surface of the door as opposed to being morticed into the edge of the door.  A nightlatch holds the door shut on a latch which can often be deadlocked into position.

Nightlatches are still sometimes referred to by their traditional name of 'rimlock' although a rimlock usually now refers to a basic security lock for use on internal doors, gates or outbuildings.



A test that covers the security and durability of an entire doorset rather than just the lock.  The new annex includes clauses covering materials, construction, tolerance, infill panels and resistance to climatic influences including a thermal cycle test.  Assessment is based on the door assembly's ability to continue to operate within specified force limits and a visual inspection for cracking, distortion and delamination.

Pivot Window Hinges/Stays

The pivot hinge is for use on high performance horizontal or vertical pivot timber windows and offers a high weight capacity for large glazed areas.


Poly Vinyl Chlorate Unplasticised is the material used to manufacture a wide range of products including windows and doors

Rim Lock

Nightlatches are still sometimes referred to by their traditional name of 'rimlock' although a rimlock usually now refers to a basic security lock for use on internal doors, gates or outbuildings


Also called follower.

A square hole created in the backset to allow the spindle to feed through to operate the handle.


Safety Glass

A glass that is designed to reduce the risk of injury when broken.

Secondary Glazing

An additional layer(s) of glazing fixed to an existing window to produce a thermal/acoustic break. This is not double glazing.


Shootbolts are used on multi-point locks to further secure the door into head and sill of the frame by an upwards movement of the sprung handle

Side Hung Window Hinges/Stays

Outward opening sashes where there is no requirement for an easy clean facility.

Snap In Door Hinge (for doors)

A symmetrical hinge used on internal light doors in either residential or commercial applications.


A button or slider on a nightlatch that enables the latch to be “held back”, preventing the door from accidentally slamming shut.


The spindle is a square metal bar which connects the door handles on either side of your door together through the follower.  When the levers of your door handles are pressed, the spindle rotates and operates the latch inside the door, allowing the door to open.

Tempered Glass

A type safety glass that has undergone a heat treatment process in order to increase its strength. Also known as toughened glass.

Thumbturn Cylinder

A knob fitted to one end of a cylinder which allows the door to be unlocked without a key from one side only

Tilt & Turn Window Hinges/Stays

The tilt & turn window are typically used where it would not be possible or advisable to open windows outwards, e.g. pathway or street, or where external shutters are fitted.

Top Hung Window Hinges/Stays

For outward opening sashes in situations where glass may be easily cleaned from the outside of the building. The unobtrusive flush fitting hinges allow the sash to be disengaged and removed when it’s opened to the horizontal position.


The United Kingdom Accreditation Service is the sole national accreditation body recognised by government to assess, against internationally agreed standards, organisations that provide certification, testing, inspection and calibration services.

Yale have a UKAS accredited test house in which many of their products are tested to the required standards.