1mm (20 gauge) thick galvanised steel door sheet
2mm (14 gauge) thick galvanised steel door frame
1.7mm (16 gauge) thick stainless steel threshold

Our steel security doors are galvanised to ensure damage does not occur due to structural degradation from rust. When a steel door is made of lower quality material, the insufficient material thickness incurs a lack of strength, resistance to attack and overall durability. By processing our materials in-house, we guarantee the strength of the steel to deliver on our promise of high-quality products.


High security as standard
Anti-drill and anti-snap locking system
Extra secure 10-point locking system designed specifically for our security doors. Tested and performing in the real world since 1999

Other door suppliers often adopt a cheap approach when specifying a locking system.  In doing so they don’t make security and durability a top priority. Our 10-point locking system has been developed since 1999 and we continue to update our system in relation to the requirements of the modern world. Our security doors are designed and tested to PAS24 which reinforces a high level of security and overall performance.


Steel Security Doors tested to 50,000 cycles

Over time steel security doors can degrade with use, especially if the components are not made of high quality material. With a Kirncroft door, you can open, close, lock, and unlock two cycles per day for over 68 years and have the assurance of a door that works properly and efficiently.

Internal construction

Galvanised steel subframe with 4mm (3/16″) round-bar steel mesh
Heavy duty fixing plates for locks, hinges and surface mounted hardware
Injected polyurethane insulation

The internal construction of our steel security doors is such that the components reinforce the strength of the door. It is important that screws securing the locks and hinges cannot become loose from inadequately thin or non-existent reinforcing plates. By constructing our security doors with hard setting injected polyurethane foam, they have an integrity beyond that of just the external steel skin and they are supported by the internal structure to last for years.


Door AND frame injected with polyuerethane insulation.
U value 1.8W/m2K

Insulation is an important aspect that is often overlooked by other suppliers, in that they use cheap material to insulate their security doors. Mineral wool and honeycomb paper insulation, when used in a steel security door, do not meet the requirements for U values for Building Regulations. Our U-value has been confirmed by an accredited laboratory, using the correct method of calculating the door and frame as a complete unit. By using polyurethane insulation, our security doors are not only structurally reinforced but also meet thermal performance requirements.


Galvanised steel inside and out
Polyurethane insulation seals internal components
Stainless steel threshold
Stainless steel locking rod tubes
304 grade stainless steel hardware

If steel security doors are not properly insulated, they can be prone to rusting from the inside out. Insulation made of mineral wool or honeycomb paper naturally collects moisture and can spread inside the steel door, decreasing its resilience to rusting. Kirncroft security doors are made of galvanised steel inside and out with polyurethane insulation that seals internal components and stops them from coming into contact with any moisture.


Fully sealed door, frame and threshold.
Advanced door and frame sealing system.

Having a fully sealed door, frame, and threshold prevents water from entering the internal components of the door and prevents them from rusting from the inside out. With our advanced sealing system, the frames and thresholds stand firm against water leaks inside your building. In turn, it eliminates the issue of needing to replace components due to water damage. Waterproofing guarantees your security door continues to provide security even when the weather takes a turn.


Grade 304 stainless steel handles as standard
Compliant with disability regulations
Tested to 200,000 cycles

Handles are a just as important aspect to a steel door as the internal components. With frequency in use, handles should match the high quality materials of the door itself. While other suppliers focus on budget security doors made of low quality materials, turning a blind eye to longevity, we include Grade 304 stainless steel handles as a standard for our doors. Each handle is compliant to regulations and is tested thoroughly before dispatch.


304 grade stainless steel fully welded anti-knockout hinges as standard

Kirncroft steel security doors use hinges with a complete stainless steel welded design, ensuring that they can endure the elements and can withstand breach attempts if the doors are attacked.

Modular Building Specialists

Anti-vandal steel window units

Built-in anti-racking tolerance

Although suitable for a wide range of applications, our products are especially designed for and have a proven track record in, the modular building industry.



Kirncroft 10-point locking steel security doors.


Anti-vandal steel window shutters offer enhanced security for modular building applications.