The GN 648.1 and the GN 648.2 zinc plated steel rod end bearings housing’s have a blue passivated finish. For the pairings, the bearing socket on the version where lubrication is possible is brass, while the self-lubricated version is steel, zinc plated. The internal ring for both is steel, hardened, ground, and polished.
The GN 648.5 and the GN 648.6 bearings have a stainless steel housing that is forged and polished. For the pairings, the version with the lubrication fitting features a bronze bearing socket with a steel internal ring that is hardened, ground, polished, and hard chrome plated. The two self-lubricated versions have pairings with a PTFE-insert, with one made of bronze and the other of stainless steel, with an internal ring that is also stainless steel