simple and convenient visual indication of bolt status


smartBolts provide an instantaneous visual indication of a loose or under-tensioned condition. The bright red-orange display of a loose fastener will gradually darken whilst tightening until it becomes deep black at design tension. The accuracy of the final indication is within 10% of the design tension. This is an ideal solution for many semi-critical applications where flange reliability is important.


  • Easy "Go, No-Go" indication

  • "Black is tight, "Red" is loose

  • Fully repeatable

  • Adjust without special tools

  • Identify bottomed-out bolts

  • Identify loose bolts 


Caveat: Although smartBolts are an acceptable solution for simple applications where a subjective or "go, no-go" indication is sufficient, applications demanding ultimate bolt stress accuracy should rely on ultrasonic elongation measurement methods. Click here for further details.

let's talk about it...