Screws Designing Safe Stainless Steel Screw Connections

How can a stainless steel bolt-and-nut connection be designed so that it is mechanically reliable, corrosion-resistant, and cost-effective? Answers to this question are provided by a current research project conducted by Wismar (Germany) University of Applied Sciences, Fraunhofer IGP, and industry partners, including Sonderschrauben Güldner. 

Screw connections are among the key structural elements in mechanical and plant engineering. They must reliably transmit forces, facilitate assembly and maintenance processes, and often remain functionally reliable for many years under varying operating conditions. 
Design becomes particularly challenging when stainless steel bolted joints are subjected to continuous cyclic loading and, at the same time, high corrosion resistance is required—for example, in energy and process engineering plants, in mechanical engineering, in maritime environments, or in applications with heightened requirements for service life and operational safety.For designers and developers, this raises a key question: How can a stainless steel bolt-nut joint be designed so that it is mechanically reliable, corrosion-resistant, and, at the same time, economically optimized? In mechanical engineering, the calculation of bolted connections is generally performed in accordance with VDI 2230 Part 1 (2015), which is internationally recognized as an important reference standard for design. A key consideration is the long-term durability of the joint. However, precisely this aspect has so far been insufficiently investigated and documented for bolt-nut joints made of stainless materials.