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Top-Quality Bottom Fixings for Your Fireplace | MI-Flex, 316L Mi-FLEX, 125MM (5 INCH) - National Flues

Upgrade your fireplace with the finest bottom fixings available at National Flues. The MI-Flex, 316L Mi-FLEX, 125MM (5 INCH) bottom fixings are crafted to offer unparalleled strength and durability, securing your flue system in place with precision. Trust in our expertise to deliver top-notch products that meet the highest industry standards.
Upgrade your fireplace with the finest bottom fixings available at National Flues. The MI-Flex, 316L Mi-FLEX, 125MM (5 INCH) bottom fixings are crafted to offer unparalleled strength and durability, securing your flue system in place with precision. Trust in our expertise to deliver top-notch products that meet the highest industry standards.


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The best selling flue liner in the UK. Suitable for gas, oil, and approved solid fuels. Call our advisers on 01670 206 999 if you need any help choosing.

£14.99 £88.99
Showing 20 of 20 items
Increasing MI-FLEX Adaptor - Ø 100-Ø 125

Increasing MI-FLEX Adaptor - Ø 100-Ø 125

20-100-MR
£20.99 (including VAT)
In stock
MI-FLEX Adaptor - Ø 125

MI-FLEX Adaptor - Ø 125

20-125-MAE
£19.99 (including VAT)
In stock
MI-FLEX Adaptor 1mm - Ø 125

MI-FLEX Adaptor 1mm - Ø 125

20-125-MAE1
£30.99 (including VAT)
In stock
Long Tail MI-FLEX Adaptor - Ø 125

Long Tail MI-FLEX Adaptor - Ø 125

20-125-MAELT
£24.99 (including VAT)
In stock
Increasing MI-FLEX Adaptor - Ø 125-Ø 150

Increasing MI-FLEX Adaptor - Ø 125-Ø 150

20-125-MR
£22.99 (including VAT)
In stock
Increasing MI-FLEX Adaptor 1mm  - Ø 125-Ø 150

Increasing MI-FLEX Adaptor 1mm - Ø 125-Ø 150

20-125-MR1
£43.99 (including VAT)
In stock
Increasing MI-FLEX Adaptor - Ø 125-Ø 175

Increasing MI-FLEX Adaptor - Ø 125-Ø 175

20-125-MRD
£68.99 (including VAT)
In stock
Long Tail Increasing MI-FLEX Adaptor - Ø 125-Ø 150

Long Tail Increasing MI-FLEX Adaptor - Ø 125-Ø 150

20-125-MRLT
£38.99 (including VAT)
In stock
Register Plate Adaptor - Ø 125

Register Plate Adaptor - Ø 125

20-125-RPA
£51.99 (including VAT)
In stock
Increasing Register Plate Adaptor - Ø 125-Ø 150

Increasing Register Plate Adaptor - Ø 125-Ø 150

20-125-RPAI
£71.99 (including VAT)
In stock
Top Hat Adaptor - Ø 125

Top Hat Adaptor - Ø 125

20-125-THA
£58.99 (including VAT)
In stock
Register Plate Adaptor - Ø 150

Register Plate Adaptor - Ø 150

20-125-THAR
£88.99 (including VAT)
In stock
MI-FLEX FastFix-Screw Adaptor to SW - Ø125

MI-FLEX FastFix-Screw Adaptor to SW - Ø125

21-125-MAE
£14.99 (including VAT)
In stock
Screw-FIX Adaptor to SW - Ø 125

Screw-FIX Adaptor to SW - Ø 125

25-125-MAE
£15.99 (including VAT)
In stock
Screw-FIX Adaptor to SW, 1mm - Ø 125

Screw-FIX Adaptor to SW, 1mm - Ø 125

25-125-MAE1
£32.99 (including VAT)
In stock
Screw-FIX Long Tail Adaptor - Ø 125

Screw-FIX Long Tail Adaptor - Ø 125

25-125-MAELT
£28.99 (including VAT)
In stock
Screw-FIX Increaser - Ø 125-150mm

Screw-FIX Increaser - Ø 125-150mm

25-125-MR
£25.99 (including VAT)
In stock
Screw-FIX Long Tail Increaser - Ø 125-150mm

Screw-FIX Long Tail Increaser - Ø 125-150mm

25-125-MRLT
£43.99 (including VAT)
In stock
Screw-FIX Register Plate Adaptor - Ø 125

Screw-FIX Register Plate Adaptor - Ø 125

25-125-RPA
£42.29 (including VAT)
In stock
Screw-FIX Register Plate Increaser - Ø 125-150mm

Screw-FIX Register Plate Increaser - Ø 125-150mm

25-125-RPAI
£57.99 (including VAT)
In stock
Your Bottom Fixings Questions Answered

Are the bottom fixings compatible with all flue systems? -

Yes, our bottom fixings are designed to be versatile and compatible with a wide range of flue systems, ensuring easy installation.

Do the fixings come with installation instructions? +

What material are the fixings made of? +

Can these fixings withstand high temperatures? +

Are the fixings suitable for outdoor fireplace installations? +

Do I need any special tools for installing these fixings? +

Are these fixings backed by a warranty? +

Can these fixings be used for chimney repairs? +

How do I know which size of bottom fixings I need for my fireplace? +

Are these fixings resistant to rust and corrosion? +

Are these fixings tested for durability and safety? +

Do these fixings require maintenance once installed? +

Can I purchase replacement parts for these fixings if needed? +

Do these fixings come with any additional accessories? +

Are these fixings suitable for use with wood-burning stoves? +

How soon can I expect delivery of these fixings after purchase? +

What is the load-bearing capacity of these fixings? +

Can these fixings be painted to match my fireplace decor? +

Do these fixings come with any anti-vibration features? +

Are these fixings suitable for use in listed buildings or heritage properties? +

Can I consult with your team for technical advice on using these fixings? +

Do these fixings meet industry standards for quality and safety? +

What is the expected lifespan of these fixings? +

When it comes to enhancing the functionality and safety of your fireplace, the choice of bottom fixings is crucial. At National Flues, we bring you the MI-Flex, 316L Mi-FLEX, 125MM (5 INCH) bottom fixings that are designed to withstand the rigors of fireplace operations. These fixings provide a secure anchor for your flue system, ensuring it stays in place for years to come. Explore our range of bottom fixings to find the perfect fit for your fireplace installation needs.
Why Buy Bottom Fixings Products
The MI-Flex, 316L Mi-FLEX, 125MM (5 INCH) bottom fixings are ideal for both residential and commercial fireplace setups. Whether you are renovating an existing fireplace or installing a new one, these fixings offer a reliable solution for securing your flue system. Enjoy peace of mind knowing that your fireplace is backed by high-quality bottom fixings that are built to last.

Trusted By Trade Professionals

Our Bottom Fixings products and services are trusted by hundreds of professionals nationwide. We're committed to providing quality and reliability that meets the high standards of our customers.

Dedicated Support

Experience our unparalleled customer service and support when you buy Bottom Fixings from National Flues. Our team is here to assist you every step of the way, ensuring your needs are met with expertise and care.

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