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SmartBolts – The ultimate way to reduce FOD

SmartBolts – The ultimate way to reduce FOD

Incredibly advanced.  Surprisingly simple.  Universal fit.

Airfield Lighting Systems Ltd (ALS) have launched SmartBolts – a Visual Indication System that turns the top head of a bolt from red to black as you tighten it.  SmartBolts give you peace of mind that your bolts are at the correct tension vital for Airfield safety.  They can be easily retrofitted to existing runway lighting systems and therafter inspections are visible rather than manual.  They do not need to be replaced with every inspection, saving you money and time.

They are manufactured in the US to rigorous standards and will fit any existing AGL fitting with their universal design.

Visual Indication System

The Visual Indication System is a method of measuring bolt tension that is embedded in every SmartBolt. This technology uses colour to indicate tension. Changes in colour are proportional to bolt stretch, ensuring accurate and reliable measurements.

Unmatched Benefits

SmartBolts improve the safety and reliability of your installed equipment for a FOD-free environment.

A real-time visual alert of tension allows hands-free inspection. Service life is extended with full repeatability, reusability, and no wearable parts. Install and inspect on-the-go with no training required.

Unprecendented Value

Remove the doubt associated with traditional nuts and reduce the maintenance frequency.  Simple installations and faster inspections reduce operational costs. Furthermore, SmartBolts provide an early warning of reductions in bolt tension, leading to increased productivity and safer Airfield operations.

How it works

The bolts work very similar to springs. When you stretch a spring, it pulls back – trying to return to its original size. The stretching force is called tension. The force that pulls back is called compression.  The tension creates clamp force holding parts together.  The coloured indicators represent a certain torque:

SmartBolts directly correlate tension with colour. Accuracy and reliably is ensured because the colour change of the Visual Indication System is proportional to bolt stretch — the only true measure of how tight your joint is (torque readings alone can be misleading since torque only measures how difficult it is to turn the bolt head).

The SmartBolts built-in visual tension indicator turns from red to black when proper tension has been reached — and is completely reversible for the life of the bolt.


  • Reduces risk of FOD.
  • Save time on runway inspections, no need to get out of the van to torque the fittings a visual inspection is all that is required.
  • No need to throw away nuts and washers each time, SmartBolts can be re-used over and over.
  • Tought and strong.
  • Long lifetime guarantee.
  • Use with Heico Combi-Lock washers for extra protection.

Taking Airfield Safety to the next level

Use SmartBolts in conjunction with
Heico-Lock Fasteners for ultimate protection.

Conventional fasteners often rely on the physics of friction instead of tension to maintain clamp load e.g. nyloc nuts, metal lock nuts, safety-wire, thread adhesives etc. but this offers limited performance.

With HEICO-LOCK® the unique tension based design of the washer system provides superior resistance to constant vibration, high dynamic loads and thermal cycling.

The HEICO-LOCK® system consists of a pre-assembled pair of washers with inclined cams on the inside and radial teeth on the outside.   Tightening of the nut/bolt creates a ‘gripping’ action of the teeth thus seating the mating surfaces.

The angle of the cams (α) between the HEICO-LOCK® washers is greater than the thread pitch (β) of the bolt. This angle means the expansion in thickness of the HEICO-LOCK® washers is greater than the possible longitudinal movement of the bolt along the thread

Interested in this product?

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