Dimensions and Mechanical Production
The high standard of quality and the large production facilities make it possible to manufacture special bolts in various sizes and tolerance classes. IHILDIS’s supply range begins with thread size M20 (3/4″). The largest thread manufactured to date by HILDIS was W510 (510 mm / 20″).
The mechanical machining of the fastening elements is carried out on state-of-the-art CNC machines with driven tools. The threads (up to M120/5″) are made by HILDIS using the cold-rolling process. Depending on size and material, the thread is cold-rolled by the continuous or recessing process. Through cold rolling, the root area of the thread is strengthened. This increases the yield strength of the bolt material in edge areas of thread flank and core fillet. At the same time, the internal compressive stresses are created which later overlap with the tensile stresses, thereby creating an overall tensile state (especially in the edge zones of the thread root), which has a positive effect on the life of the bolt.