Aluminothermic Welding

AutoSeal® Moulds

AutoSeal® moulds are Pandrol’s newest aluminothermic welding innovation that streamlines the welding process.

AutoSeal® Moulds product overview

The built-in felt expands during the preheating phase of welding, creating a tight seal between the mould and rail. This completely removes the need for luting with paste or sand, whilst preventing welding leaks. They are the world’s first self-sealing moulds and bring numerous benefits including faster welding speeds, enhanced welder ergonomics, increased reliability, and reduced waste.

  • This new technology has been developed by our welding experts and is compatible with Vignol and Grooved rail.
  • AutoSeal® moulds are recommended for the most demanding rail networks, meeting the needs of short possession times and high safety standards.

Advantages of using AutoSeal® Moulds


Time saving

Using AutoSeal® saves three to five minutes per weld, as the mould is sealed automatically and there is no need for the luting procedure.


Eco friendly

It is environmentally friendly, as the mould design reduces plastic waste and saves on the energy needed to produce and transport traditional luting material.



The self-sealing felt is more reliable than manual sealing, especially in cold weather and tight spaces.


Enhanced wellness for workers

AutoSeal® promotes the welder’s health and wellbeing, reducing stress and time spent kneeling.


Low defect rate

Using AutoSeal® reduces the defect rate by facilitating moisture evacuation during the preheat.


Functional and effective

The moulds are compatible with vignole and groove rails, meeting the demands of short possession times and high safety standards.

Technical features of AutoSeal® Moulds


Automatic sealing

A built-in expansive strip automatically expands during the preheating phase of welding and creates a tight seal between the mould and the rail.


Felted mould

The mould is equipped of compressive felt to perfectly fit the rail profile, removing the need to manually grind the mould against the rail during the setup.


Moisture escape

Moisture during the preheating process can cause defects. The AutoSeal® mould allows moisture to escape more easily than with luting.


Environmentally friendly

The moulds reduce plastic waste and the amount of energy needed for production and transportation.



AutoSeal® moulds are compatible with vignole and grooved rail.


Compatible with worn rails

The AutoSeal® mould in its standard configuration can weld rail up to 3mm wear. Welding up to 6mm wear or more is possible with adapted procedure.

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