Estimation of screw diameters

according to VDI guideline 22301)

The following procedure allows a rough estimate to be made of the required screw dimensions for a particular screwed connection and temperature around 20 °C, in correspondence with the details in VDI 2230. The result should be checked mathematically in each case.

1) VDI = Verein Deutscher Ingenieure

A Select in column 1 the next higher force to the work force FA,Q acting on the bolted joint.

B The required minimum preload FM min is found by proceeding from this number:

Estimation of screw diameters

C The required maximum preload force FM max is found by proceeding from this force FM min by:

Estimation of screw diameters

D Once the preload (force) has been estimated, the correct screw size is found next to it in column 2 to 4 underneath the appropriate strength class.


A joint is loaded dynamically and eccentrically by the axial force FA = 8500 N. The screw of strength class 12.9 will be assembled with a manual torque wrench.
A 10 000 N is the next higher force to FA in column 1
B 2 steps for «eccentric and dynamic axial force» lead to FM min = 25 000 N
C 1 step for «tightening with manual torque wrench» leads to FM max = 40 000 N
D For FM max = 40 000 N thread size M10 is found in column 2 (property class 12.9)

Estimation of screw diameters

Login to download the document (PDF) 

For the purpose of providing services, this website uses cookies. You will consent to this by clicking on “OK” and/or using our services.
Please click on privacy policy to find the information on cookies and the possibilities for modifying the terms of their storage.