Glossary of Terms

When it comes to steel door terminology, there’s a lot of acronyms and phrases to familiarise yourself with. We’ve compiled this glossary of terms to act as a useful guide next time you require steel doors on a project.

Acoustic Rated – Designed to reduce the spread of noise between rooms.

Aperture – The hole/opening in a door where a pane of glass will be fitted.

Architrave – The door frame.

British Standards – An internationally recognized standard governed by BSI (British Standards Institution) to ensure they are safe and high quality, ready for use in buildings.

CE Marking – Stands for “Conformité Européene” which translates to European Conformity. CE marking is used in the testing of products to certify that it meets the required EU safety, health and environmental protection requirements.

Closer – An accessory used at the top of a door which uses mechanical force to pull the steel door back to the closed position and self-close the door.

Cylinder Locks – A key operated lock that is operated by moving 5 or more pins to enable the cylinder to move freely which then unlocks the door.

dB Rating – dB stands for decibels and relates to sound levels. Any noise above 70 dB for a prolonged period can potentially damage your hearing. A dB rating will be used when testing and installing acoustic steel doors.

Dead Locks – A rotating cylinder is used and can be operated from either one side (single cylinder) or both (double cylinder) with a key.

Deadbolt – A latch lock that securely closes the door by placing a receiver into the door’s frame or jamb.

Door latches – A mechanism that secures the door in place by moving into a pre-cut hole in the door frame. It is retracted through turning a handle or doorknob.

Door leaf – Any door featuring a single panel that fills a doorway.

Door set – Doors which come with an assortment of compatible hardware that allow for a quick and easy installation of a full door. External door sets are often supplied with various security hardware on top of the standard fitting accessories (e.g. hinges and handles)

External Door – Connects a room to the outside of the building. External doors will often have additional security features to prevent or deter unwanted entry.

FD – Any combination of ‘FD’ followed by a number indicates a fire door which has been checked in accordance with official regulations and has been tested. For example, an FD30 is a fire door which has been tested to withstand at least 30 minutes of fire. Additionally, there may be FD30s; the ‘s’ pertains to a smoke rating.

Fire Door – Manufactured to provide protection in the event of a fire by enabling the safe escape of any persons in the building. Fire doors can vary in terms of their rating from 30 minutes up to 240. For a fire door to be legally compliant it will have been through rigorous testing to ensure it conforms to all relevant British standards. For more information, read our blog on fire door safety here: <Insert Link>

Glazed Door – A door with glass panels.

Handing – This is a term used for pair doors. It describes the door that is opened first and away from you e.g. a right handing would open away from you with the hinges on the right.

Hanging – The act of fitting the door into the frame.

Hinge – The plates and pins used to attach the panels to the door frame. They can swing either inwards or outwards.

Infill Panels – If a door is slightly too small for the space, infill panels will fill the gap to give a flush fit.

Internal Door – Used within the inside of a building to connect rooms. They are often lighter than external doors with less security functions but are often fire rated to ensure safety.

Intumescent Strip – Used to enhance safety features of a fire door, the intumescent seal expands when exposed to heat and closes the gap between the door and its frame to stop the spread of fire and smoke.

Louvre door – Allows some light and airflow through horizontal slats. They are often used for spaces that require fresh air passage such as data centres, plant or switch rooms.

Mastic – An adhesive/sealant used to bond two elements together e.g. sealing the gap between the door and the architrave.

Mortise Lock – A mortise lock is one of the most secure forms of residential hardware available. ‘Mortise’ refers to the hole or recess that allows the lock to be inserted into the door.

Panic Bar – Also known as ‘crash bars’, they are used on external doors to quickly and safely allow exit from a building in the event of an emergency.

RAL – A specialized colour chart created by the RAL colour institute.

Security Door – Used to prevent unauthorized entry from intruders. We offer a range of security doors from SR1 – PAS24.

Threshold – Found at the bottom of a doorway to join one space with another, commonly made of metal or wood. It will help to close the gap between the bottom of the door and the floor.


Ready to discuss a project?