The piston pin connects the piston with the connecting rod. The designer - exactly like with the piston must pay attention to the weight.
The piston pin is mostly either mounted fully floating in the piston or in the small connecting rod with very few play. In some cases it is both. A protection device to protect the cylinder wall against damage caused by the piston pin is especially important. For protection, round wires or circlips (for diesel engines) are used. For this grooves are implemented in the piston pin bore of the piston.
The piston pin is made hollow and features either a constant cross section, or it is strengthened in the middle. Two-stroke engines may have drillings that are interrupted to avoid a connection of channels and therefore scavenging losses. It is produced most often from low-carbon steel and is hardened at the surface. High demand piston pins consist of nitriding steels.
The piston pins which are mounted fully floating in the connecting rod can be inserted more easily if you heat the piston to approx. 80°C. 05/08