This is one of Hjerno Tool Factory's long-time specialties that we have manufactured for over 25 years – and we sell both collapsible cores as an integral part of our own finished tool solutions, but also separate custom-made collapsible cores for other tool manufacturers and toolmaker suppliers.
We have developed our own unique models and manufacturing methods that make these collapsible cores extremely precise and durable, partly with the help of a special surface treatment, and our collapsible cores are therefore good for many millions of shuts.
We have many different model designs in our system ready to produce the collapsible cores from, but we also manufacture special collapsible cores which can often handle the most incredible undercuts or threads, where we can control both the starting and stopping of threads with 1/100 mm accuracy.