Liquid nitriding is a subcritical surface enhancement process with one of the longest track records of success of any case hardening technology.
PVD coatings involve the deposition of thin (2-10 microns; 0.0001" – 0.0004") films on the surface of tools and components.
The advantage of a spherical plain bearing compared to bushings is to accept alignment errors, angular misalignment or deformation of components during operation (bending of pins, etc.) and wide tolerances.
HEF applies the same technology used on bushings to spherical plain bearings.