What is the minimum thread length on high-strength structural bolting assemblies for preloading?

The minimum thread length is calculated strictly according to EN 14399-3 for high-strength structural bolting assemblies for preloading - System HR and EN 14399-7 for high-strength structural countersunk bolting assemblies for preloading - System HR .

In calculation, you need to consider standard reference thread length (b), minimum length of the shank - un-threaded part of the bolt, and distance from the head of the bolt till the first full thread.

To help with that, we have created two useful calculators:

In any doubts, please contact our Quality Department .

↫ Go back