| Part | Full Title | Focus | |------|------------|-------| | | Joints with one cylindrical bolt | Calculation method for concentric and eccentric clamping, concentric/eccentric loading, with or without preload. | | Part 2 | Joints with several bolts | Load distribution, tightening sequences, and multi-bolted joint systems. |

The previous calculation for alternating stress (fatigue) was linear. The 2021 update introduces a approach (similar to the Palmgren-Miner rule).

To understand the significance of the 2021 update, one must look at its predecessor. VDI 2230 Part 1 (2003/2015) provided a comprehensive analytical method for calculating steel bolted joints. While robust, the 2003 version struggled to keep pace with the rapid advancement of material science, particularly in the automotive and aerospace sectors. The rise of multi-material mix designs—combining steel, aluminum, magnesium, and plastics—exposed the limitations of the previous standard, which relied heavily on specific material constants applicable primarily to steel-on-steel connections.