Design to succeed 23 August 2018

When designing a fastener connection how can you make sure you select the most economic option available without compromising on safety? The answer is simple – test it. The only thing needed is equipment that allows you to verify a bolted joint’s structural integrity under operating stress conditions before putting it to use.

VibrationMaster’s test benches enables just that. A bolted joint can be tightened to the specified torque and/or pretension load while monitoring these essential assembly parameters. Plus the friction coefficient in the threads and under the bolt head or nut, as well as the clamping surfaces can also be recorded.

Then, the assembly is subjected to transverse load conditions while monitoring the real time clamping force to assess a bolted joint’s structural integrity. As the equipment allows strict adherence to the standardised stress profiles of the well publicised DIN 25201-4 and ISO 16130 protocol, there is no ambiguity with regard to the relevance of the testing.

In most cases it’s likely to follow the vibration stress profile (amplitude and force and frequency) as suggested by the standardised protocol. This will return results in a matter of only minutes of vibration testing.

A series of comparative testing of different types of fasteners can be ran this way, be it on the bolt side or on the nut side. Investigations can include special materials used or surface finishes applied, or even special manufacturing procedures utilised, or the effect of accessories like washers, securing elements and/or different types of lubrications and chemical locking techniques.

By being able to run a strict and repeatable regime of stress patterns, confidence can be gained in the design and the user gets into a position to explore design options they probably did not even consider thus far.

The J121 portable version of the test bench allows the structural integrity assessment of bolt diameters of up to M16. The bigger machines are for bolt sizes of M30 (J600) and even M45 (J900). Also, for these two bigger benches, the vibration amplitude and transverse force can be controlled continuously and independently from each other.

Deputy Editor

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889


Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.