https://mechcalc.net/blog/en/categories/bolted-joints/ Recent content in Bolted Joints on MechCalc how-to Guide https://mechcalc.net/blog/og-default.png https://mechcalc.net/blog/og-default.png Hugo en Mon, 20 Apr 2026 20:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-10-eccentric-load-bending/ Mon, 20 Apr 2026 20:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-10-eccentric-load-bending/ The most complex part of VDI 2230: eccentric clamping and eccentric loading. This article explains the physical meaning of the eccentricity parameters ssym and a, the calculation of the corrected resiliences δP* and δP**, the substitutional moment of inertia IBers, and the key formulas of the opening check. https://mechcalc.net/blog/en/posts/vdi2230-09-worked-example-esv/ Mon, 20 Apr 2026 19:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-09-worked-example-esv/ A full VDI 2230 tapped-thread joint (ESV/TTJ) worked example. Compared with the previous DSV example, it highlights the key ESV differences in the resilience calculation, the nut-region elastic modulus, and the engagement-depth check. https://mechcalc.net/blog/en/posts/vdi2230-08-worked-example-dsv/ Mon, 20 Apr 2026 18:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-08-worked-example-dsv/ A full VDI 2230 through-bolt joint (DSV) worked example, going through R0–R13 in all 14 steps. It includes the specific input parameters, the intermediate result of each step and the final safety factors, tying the theory of the previous 7 articles into one executable calculation chain. https://mechcalc.net/blog/en/posts/vdi2230-07-strength-check-r7-r13/ Mon, 20 Apr 2026 17:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-07-strength-check-r7-r13/ The lower half of the VDI 2230 calculation chain — six strength checks (assembly stress, service stress, fatigue, bearing pressure, engagement depth, slip) plus the tightening torque R13. Each check's physical meaning, formula and safety factor explained one by one. https://mechcalc.net/blog/en/posts/vdi2230-06-preload-design-r1-r6/ Mon, 20 Apr 2026 16:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-06-preload-design-r1-r6/ The upper half of the VDI 2230 calculation chain R1–R6 explained: the tightening factor αA, the three sources of the minimum clamping force FKerf, the choice of force-ratio Φ formula, preload loss (embedding + thermal expansion), and the derivation of the minimum and maximum assembly preload. https://mechcalc.net/blog/en/posts/vdi2230-05-clamped-parts-resilience-cone/ Mon, 20 Apr 2026 15:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-05-clamped-parts-resilience-cone/ VDI 2230 uses an equivalent deformation cone (Ersatzverformungskegel) to model the compression zone of the clamped parts. This article explains the cone-angle formula, the cone-plus-sleeve combined model, multi-layer plate handling, and the key differences between DSV and ESV. https://mechcalc.net/blog/en/posts/vdi2230-04-bolt-elastic-resilience/ Mon, 20 Apr 2026 14:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-04-bolt-elastic-resilience/ VDI 2230 breaks a real bolt into a chain of series cylindrical segments to compute its total elastic resilience δS. This article walks through the substitutional lengths and resilience formulas of the head, shank, free thread, engaged thread and nut region one by one, and explains the difference between DSV and ESV. https://mechcalc.net/blog/en/posts/vdi2230-03-spring-model-force-distribution/ Mon, 20 Apr 2026 12:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-03-spring-model-force-distribution/ A detailed look at the core physical model of VDI 2230: the spring model (Federmodell), the elastic resiliences δS and δP, the joint diagram (Verspannungsschaubild), the physical meaning of the force ratio Φ, and the full derivation logic of the main equation Eq.16. https://mechcalc.net/blog/en/posts/vdi2230-02-scope-and-positioning/ Mon, 20 Apr 2026 11:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-02-scope-and-positioning/ The applicability conditions of VDI 2230 Blatt 1, the interface limiting dimension G, the family of standards it depends on, and the implicit premise about how force is transmitted. Making clear what the standard can and cannot compute, so you avoid applying it blindly in the wrong scenario. https://mechcalc.net/blog/en/posts/vdi2230-01-why-systematic-calculation/ Mon, 20 Apr 2026 10:00:00 +0200 https://mechcalc.net/blog/en/posts/vdi2230-01-why-systematic-calculation/ VDI 2230 is the globally recognized standard for the systematic calculation of high-strength bolted joints. This article explains the shortcomings of a simple strength check, the 14-step VDI 2230 calculation chain and the physical meaning of its main equation, to help engineers see why systematic bolt calculation is necessary. https://mechcalc.net/blog/en/posts/bolt-preselection-04-bearing-pressure/ Mon, 13 Apr 2026 21:15:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-04-bearing-pressure/ Why does a bolted joint fail as a whole when the surface is only crushed a tiny bit? This article uses the model of a 'stretched rubber band clamping a sponge' to see through the mechanics of the bearing-pressure check: from microscopic peak crushing and macroscopic embedding (Setzen), to the elastic recoil that causes an irreversible loss of preload (clamping force), to the chain failure of loosening and fatigue fracture — and gives engineering measures such as controlling the limiting surface pressure and enlarging the bearing area. https://mechcalc.net/blog/en/posts/bolt-preselection-03-quick-table/ Mon, 13 Apr 2026 18:20:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-03-quick-table/ No calculation needed — one table for a preliminary estimate of bolt size! This article gives the minimal table-lookup method for bolt pre-selection: knowing only the maximum working load a single bolt carries — axial static load, axial dynamic load or transverse shear force — you can read the recommended nominal diameter (M4 and up) and the minimum property-class combination straight from the load-range table, a result in seconds, good for quick estimates on the shop floor and in technical discussion; for a precise calculation switch to the Kübler equation or the full VDI 2230 method. https://mechcalc.net/blog/en/posts/bolt-preselection-02-reduction-factors/ Mon, 13 Apr 2026 18:00:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-02-reduction-factors/ Where does the reduction factor κ in bolt pre-selection come from? Starting from the two-way stress state where axial tensile stress and torsional shear stress combine during tightening, this article uses the von Mises yield criterion to derive the definition, formula and engineering values of κ, explaining how thread friction acts like an 'invisible tax' that cuts the bolt's axial load capacity, and why it appears in the denominator of the Kübler equation. https://mechcalc.net/blog/en/posts/bolt-preselection-01-load-to-size/ Thu, 26 Mar 2026 20:58:00 +0100 https://mechcalc.net/blog/en/posts/bolt-preselection-01-load-to-size/ For a given working load, how large should the bolt be? This article covers the preliminary design and pre-selection of bolts: first read the nominal diameter and property class from a quick pre-selection table by load range, then use the Kübler equation to back out the thread stress cross-section from the axial working load and the required clamping force, combined with the tightening factor, reduction factor and simplified fatigue and bearing-pressure checks, to help engineers quickly size a bolt in the early design stage. https://mechcalc.net/blog/en/posts/bolt-basics-01-thread-geometry/ Sun, 22 Mar 2026 22:58:00 +0100 https://mechcalc.net/blog/en/posts/bolt-basics-01-thread-geometry/ The bolted joint is one of the most widely used connection methods in mechanical engineering. Starting from the inclined-plane nature of a thread, this article sets out thread geometry and classification: the lead angle, the pitch, the pitch diameter d2, the minor diameter d3 and other key geometry parameters; common thread profiles and technical standards such as metric ISO coarse/fine, pipe threads and trapezoidal threads; and the functional distinction between fastening bolts, motion screws and sealing/adjusting bolts — laying the geometric groundwork for the later bolt strength calculation and pre-selection.