Verify that the surface pressure under the bolt head or nut does not crush the clamped material (

: VDI 2230:2021 provides a systematic approach to calculating the strength of bolted joints under various loading conditions. This includes the consideration of preload, axial and shear loads, and the influence of cyclic loading.

Embedding occurs as surface irregularities (such as roughness peaks and valleys) settle after tightening and initial operation. The resulting preload loss, FZ, is calculated as:

This balance is visualised through a joint diagram, which relates the assembly preload to the elastic resilience of both the bolt and the clamped parts. Systematic Calculation Steps