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Merford M-series M56L door.
M-series custom doors

M-series M56L

Steel door with customisable features, functions, sizes and accessories.

Weighted sound reduction index Rw = 56 dB

Suitable for indoor and outdoor applications

Available from 40 working days

We're ready to help – available on weekdays from 09:00 to 17:00.
Description

The M-series M56L is a high-performance steel door developed for environments where maximum sound insulation is essential. This door combines exceptional acoustic performance with a robust and durable construction, effectively controlling noise in industrial, commercial and technical environments. The M56L is available as a single or double leaf and can be manufactured to open left- or right-handed, allowing easy integration into a wide range of installations. With a weighted sound reduction of Rw = 56 dB, the M-series M56L delivers outstanding noise control.

The door has a standard door leaf thickness of 100 mm and a mass of approximately 68 kg/m². Compared with the M-series M56, the M56L has a thicker and heavier door leaf, providing greater rigidity and improved performance at lower frequencies. The M56L offers a solid foundation for applications primarily focused on acoustic performance.

The door features a durable double-skin construction with galvanised steel sheets. The M-series M56L can be finished in any RAL colour, ensuring both technical performance and architectural consistency across all applications. For applications requiring fire resistance, the M-series M56 is available with certified fire resistance classifications in accordance with EN 1634-1 / NEN 6069.

Core features
Fundamental properties that define performance.
CE certification
EN 14351-1.
Sound insulation
Weighted sound reduction index Rw = 56 dB.
Fire resistance
Smoke control
Burglary resistance
Optional RC2 or RC3 classification (EN 1627 / NEN 5096).
Bullet resistance
Air and gas tightness
Additional functions
Additional functions that enhance safety and control.
Anti-panic function
Optional panic (EN 1125) or emergency (EN 179) hardware.
Access control
Optional access control systems, including key, card, code, biometric and electronic options.
Specialised options
Solutions for highly specific technical environments.
Ventilation
ATEX model
Available as ATEX-compliant version.
Transformer model
Properties

The features above can be combined and tailored to your project. For more custom possibilities, or guidance in selecting the right door, our specialists are happy to help you find the best solution for your application.

Applications

M-series doors are suitable for integration in standard building façades, as well as in technical housings and industrial enclosures. They are commonly used in transformer and electrical rooms, mechanical spaces, data centres, laboratories and other facilities where safety, durability and performance are essential.

Downloads and specifications

For complete technical specifications, manuals and certificates, refer to the documents below.
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Answers to common questions

Answers to the most common technical and practical questions.
Are Merford doors energy efficient?

Merford doors can be made airtight and thermally insulated, contributing to energy savings in buildings and supporting sustainability targets.

Does Merford provide service and maintenance for doors?

Yes, we provide comprehensive service and maintenance for all our doors. Our specialists carry out periodic inspections, check mechanical and electronic components, and ensure the doors maintain their original performance in terms of sound insulation, fire resistance, and security. This guarantees long-term reliability and optimal operation, even in demanding environments. Service can be provided on a contract basis or as a one-time request.

Are M-series doors suitable for custom designs and special dimensions?

Yes, our doors are available in custom widths, heights, leaf configurations, and finishes, suitable for both new builds and renovations.

Which performance features can I combine in a single door?

Our M-series doors can combine sound insulation, fire resistance, smoke control, burglary, or bullet resistance in a single door. Depending on the project, ventilation, ATEX safety, transformer protection, or anti-panic functionality can also be added, though not all features can always be combined simultaneously.