The best way to ensure the correct bolt pretension

Achieving the correct bolt pretension is essential in assuring bolted joint integrity. In this context, ultrasonic measurement has proven to be a very accurate and cost-effective solution when installing new bolts as well as when evaluating existing bolts as part of determining the lifespan of wind turbines.

By using the ultrasonic measurement tool, you can achieve the right alignment of bolted joints efficiently and in a controlled manner. The tool is suitable for most bolt types and requires no special pre-treatment of the bolts. It can play an important part in maximising the operating time of the turbine, while minimising failure.

When installing new bolts, the tool allows you to track the clamp force during the entire tightening process and determine the clamp load without influencing joint stiffness. Subsequently, the data can be used to schedule service and maintenance, since the correct pretension is known from the beginning.

The advantages include:

  • A simplified method of measurement
  • Cost-effective solution
  • No special pre-treatment of the bolts required
  • Suitable for most bolt types
  • High accuracy
  • Effective and reliable process
  • Optional subsequent control measurement
  • Temperature compensation
  • Forms of cooperation


  • GWO-certified staff
  • Equipment
  • Documentation
  • Optional service agreement


  • Supervision of your team

    Operator course:

  • Education of your team by our specialists

    Verification test:

  • Check if your bolts comply with the requirements and specifications


  • Bolt lubrication machine
  • Ultrasonic measurement equipment
  • How to use the ultrasonic measurement tool

    Watch the video and get a glimpse of how you can achieve the correct pretension by using Ultrasonic Clamp Load Testing

    How can we help you?

    Contact persons
    R&D Contact Søren
    Søren Kellenberger
    Business Unit Director / Head of Sales - Global
    R&D Contact Flemming
    Flemming Nielsen
    Senior Project Engineer - Bolt & Measurement Inquiries
    Send us a message