Hydraulic tension tightening

For reliable, uniform and fast industrial tightening

Bolted assemblies are without a doubt the most widely used mechanical connecting systems.
We know that amongst the different causes of failure (overloading, design flaw, manufacturing defect, etc.), the most frequent one is poor assembly. It is therefore essential to have perfect control over the levels of tightening force and the precision with which it is achieved in order to obtain the required performance for the bolted assembly. The optimum solution for accomplishing this is tightening by hydraulic tensioning.

Hydraulic tensioning by elongation of the screw makes it possible to develop a great tension force for tightening bolts without any torsional stress or friction, but with high precision and very good repeatability.

Why opt for hydraulic tension tightening?

Hydraulic tension tightening characteristics

Compared with traditional tightening methods, hydraulic tension tightening has the following main characteristics:

  • Tension generated by hydraulic pressure
  • Axial tension that can be as great as the bolt’s yield strength
  • Tightening force contained in the tool
Technical advantages of hydraulic tension tightening

These characteristics provide the following technical advantages:

  • No stray torsion or bending stress in the bolts
  • High-precision and very uniform tightening
  • Very well suited for simultaneous tightening, facilitating automation
  • Compatible with all types of material (stainless steel, titanium, composite materials)
  • Applicable to all bolt sizes
  • Reduced number and size of bolts
  • Possibility of frequent and easy installation and removal
  • Preservation of the surfaces in contact and less wear on the bolted assembly
  • No bearing point reaction
Benefits of hydraulic tension tightening for the customer

In the end, the benefits for the customer are:

  • Maximum reliability of the bolted assembly
  • Time-saving
  • Reduced implementation, checking and maintenance costs
  • Lower risk of loosening
  • Greater operating safety

The SKF hydraulic tension tightening solutions

SKF logo