https://mechcalc.net/blog/en/tags/reduction-factor/ Recent content in Reduction Factor on MechCalc how-to Guide https://mechcalc.net/blog/og-default.png https://mechcalc.net/blog/og-default.png Hugo en Mon, 13 Apr 2026 18:00:00 +0200 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.