Screwed thread connections

Determination of the bolt size according to VDI guideline

schroefdraadverbindingIn column 1 of the table choose the next larger power than the operational axial or transverse load F.

The minimum standard tension force FMmin is found by the following method:

  • Four steps * for static or dynamic shear force according to figure A. Two steps for dynamic and excentric gripping axial force according to figure B.
  • One step for dynamic and centric or static excentric gripping force according to figure C.
  • Zero steps for static and centric gripping axial force according to figure D.
  • Two steps at tightening with a simple screw device with adjustable tightening moment or one step in tightening with a torque wrench or precision screw device or zero steps to tighten under the control of the angular rotation in the plastic area.

Subsequently you will find in the table column 2, 3 or 4 the respective bolt diameter per quality.
* steps see column 1 of the next table.
PLEASE NOTE: the step methodology gives a quick approach of the bolt size. The outcome is on the safe side. An exact calculation usually results in a smaller size.

1 2 3 4
Table Diameter in mm / strengthclass
Power in N 12.9 10.9 8.8
250
400
630
1000
1600 3 3 3
2500 3 3 4
4000 4 4 5
6300 4 5 8
10000 5 6 8
16000 6 8 10
25000 8 10 14
40000 10 12 16
63000 12 14 20
100000 16 16 24
160000 20 20 30
250000 24 27
400000 30 36
630000 36