BUMAX provides university flow test rig with corrosion resistant fastener solution


The Technische Universität Darmstadt has selected BUMAX screws for its annular gap flow test rig to ensure high-strength and corrosion resistance for critical fasteners.

Demanding test rig application

BUMAX® 109 fasteners were selected as they provide excellent corrosion resistance and high strength in the most demanding of applications.

“The BUMAX fasteners will be used to hold the sample of our annular gap flow test rig and they will be constantly immersed in water,” explains Dr. Ing. Maximilian Kuhr, Chair of Fluid Systems at the Technische Universität Darmstadt, Germany. “The high strength and excellent corrosion resistance of BUMAX screws make them ideal for our requirements.”

The test rig is used to determine the static and dynamic properties of annular gaps, such as media-lubricated plain bearings and annular seals, under turbulent flow conditions.

Replacing zinc-laminated screws for enhanced properties

“We previously used zinc-laminated 12.9 steel screws, but these quickly corroded and had to be regularly replaced as they were constantly immersed in water,” says Kuhr. “Besides excellent corrosion resistance, we switched to BUMAX because we also require high strength to ensure that the test specimen stays in place even at the highest pressure differences in our test rig.”

BUMAX® 109 outperforms standard fasteners in terms of yield strength, corrosion resistance, mechanical properties and magnetic permeability. These enhanced properties are achieved through a higher molybdenum content (minimum 2.5%), unique BUMAX manufacturing processes and the sourcing of highest quality European raw material.

Watch this space for how the test rig with BUMAX performs

The test rig with BUMAX screws has been in use from the end of August. We will provide an update on the performance of the BUMAX screws in the coming months.

“It will be exciting to see how much longer our BUMAX screws last than the zinc-laminated steel screws we previously used,” concludes Kuhr. “We hope they will last at least a year before requiring replacement, which would ensure significant time savings and reduced financial costs for our team.”


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