What is hirth joints?

Hirth joints are precision-machined joints used in engineering and machine tool applications. They are mostly found in rotary and indexing tables and are used to provide high accuracy, repeatability, and rigidity in these applications. The joints consist of two matching, hardened and ground, radial faces with a series of fine teeth cut into them. The teeth provide precise angular positioning and alignment of the two components. Hirth joints have excellent concentricity, high load-carrying capacity, and are self-centering. They are widely used in the aerospace, automotive, and machine tool industries due to their accuracy and reliability.