{"id":1252,"date":"2024-10-14T12:58:06","date_gmt":"2024-10-14T10:58:06","guid":{"rendered":"https:\/\/www.elbcore-engineers.de\/blog\/vdi-2230-the-guideline-for-safe-bolted-joints\/"},"modified":"2026-03-16T14:06:59","modified_gmt":"2026-03-16T13:06:59","slug":"vdi-2230","status":"publish","type":"blog","link":"https:\/\/www.elbcore-engineers.de\/en\/blog\/vdi-2230\/","title":{"rendered":"VDI 2230: The Guideline for Safe Bolted Connections"},"content":{"rendered":"\n

A type of connection that is ubiquitous today and found in almost all machines, plants, and steel structures is the bolted connection<\/strong>. Bolts differ in terms of their size, strength, and design (e.g., hex head bolt). While through-bolted connections (DSV) with a nut are frequently used in steel construction, screw-in connections (ESV) are common in machines and plants. In this case, the nut thread is cut into the head plate, where the bolts are later screwed in during assembly. The verification of bolted connections (DSV and ESV) is indispensable to ensure safe operation and prevent damage to people and machinery. <\/p>\n\n

A particularly well-structured and reliable method for verifying cylindrical single-bolt connections, not to be confused with ESV (as this always concerns the verification of a single bolt), is provided by the internationally recognized VDI 2230 guideline<\/strong> \u2013 Systematic Calculation of Highly Stressed Bolted Connections<\/a>. Unlike other common guidelines and standards, VDI 2230 offers a verification method for screw-in connections that is not available, for example, in Eurocode 3 (DIN EN 1993). The verification involves a total of 13 calculation steps to ensure that the forces occurring can be absorbed by the bolted connection and the clamped parts. The VDI 2230 assumes that occurring shear forces are transmitted by the friction contact of the clamped parts for the assembly condition, and the connection is primarily exposed only to bending moments and tensile forces. <\/p>\n\n

VDI 2230: A Systematic Explanation of the Calculation Steps<\/h2>\n\n

In the first step, R1, the tightening procedure<\/strong> must first be defined. This has a major influence on the forces present within the connection, depending on the scatter factor. For example, common tightening with an impact wrench is particularly imprecise and can lead to scatter of more than 60% according to VDI 2230. <\/p>\n\n

In R2, the required minimum clamping force must be determined analytically, depending on occurring shear forces or a required minimum sealing clamping force<\/strong>. Especially in complex systems and machines, the analytical determination of these forces is difficult, which is why simulation offers a decisive advantage here. <\/p>\n\n

Depending on the bolt and the clamped parts, the next step, R3, determines how the operating force of the bolt<\/strong> is distributed and what changes in length are to be expected in the bolt. A numerical detailed model is particularly suitable for determining the compliance of the clamped plates to obtain highly accurate values here. <\/p>\n\n

If connections are tightened or loosened multiple times, a smoothing of the thread occurs, which leads to so-called setting losses within the bolted connection and reduces the clamping force. Therefore, in R4, among other things, the setting force<\/strong> that occurs is calculated, depending on the type of load on the bolt. <\/p>\n\n

Based on the previously determined values, the minimum and maximum assembly preload of the bolt<\/strong> can be determined, which must be below the permissible assembly preload, depending on friction and strength class. The influence of the tightening procedure is particularly evident here, which can lead to large differences. In daily project work, we, as experts, frequently advise our customers at this point on which methods might be more suitable and thus find the optimal solution. <\/p>\n\n

In the subsequent steps R8 and R9, it is verified that the occurring static and cyclic forces<\/strong> can be absorbed by the bolted connection. During operation, additional forces can occur in the bolt, which increase the resulting stresses in the bolt, e.g., due to thermal expansion. It must be ensured here that the occurring stresses are below the permissible values, e.g., 640 N\/mm\u00b2 for strength class 8.8. The cyclic or dynamic loads must also be below the permissible amplitude, whereby special reduction factors must be taken into account here, such as hot-dip galvanizing. <\/p>\n\n

Additionally, in R10, it is possible to verify that the surface pressure under the bolt head<\/strong> is within the permissible values for the material of the clamped parts. The smallest contact area and thus a maximum surface pressure are determined. If it is a screw-in connection (ESV), an engagement depth<\/strong> can be determined in R11, depending on the nut material. If it is also a slip-resistant connection, the safety against slipping and additionally against shearing can be determined in the penultimate step, R12. <\/p>\n\n

As a final step, in R13, the required tightening torque<\/strong> is determined, depending on the friction in the thread and under the bolt head. This value is often of great interest for generating final specifications on manufacturing drawings. <\/p>\n\n

VDI 2230: A Conclusion on the Guideline<\/h2>\n\n

The VDI 2230<\/strong> is an indispensable guideline for the safe and efficient assessment of bolted connections<\/a>. As a service provider for numerical simulations, we use this guideline daily to ensure that the bolted connections we assess meet the highest standards. The structured processes, comprehensive calculation methods, and international recognition make VDI 2230 an indispensable tool in engineering practice. By applying this guideline, we contribute to ensuring the safety and reliability of our customers’ designs worldwide. If you are also facing the challenge of having to assess your bolted connections, please contact us. We will support you at any time with our expertise and full commitment. <\/p>\n","protected":false},"excerpt":{"rendered":"

A type of connection that is ubiquitous today and found in almost all machines, plants, and steel structures is the bolted connection. Bolts differ in terms of their size, strength, and design (e.g., hex head bolt). While through-bolted connections (DSV) with a nut are frequently used in steel construction, screw-in connections (ESV) are common in […]<\/p>\n","protected":false},"featured_media":651,"template":"","class_list":["post-1252","blog","type-blog","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/www.elbcore-engineers.de\/en\/wp-json\/wp\/v2\/blog\/1252","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.elbcore-engineers.de\/en\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.elbcore-engineers.de\/en\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.elbcore-engineers.de\/en\/wp-json\/wp\/v2\/media\/651"}],"wp:attachment":[{"href":"https:\/\/www.elbcore-engineers.de\/en\/wp-json\/wp\/v2\/media?parent=1252"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}