3) Heat Treatment
Chain wear is directly affected by the hardness of the wearing components. The harder the parts, the longer the wear life. End users are usually aware of this and apply that mindset to predict the lifespan of their chains. However, end users sometimes sacrifice component hardness or resistance in place of overloading the chain when using lower rated chains in higher load applications. Doing this will cause the chain to emit more heat.
As more heat is being emitted, the material the chain is made of will play a larger role. Low carbon steel for barrels will not respond to heat treatment, even if it is put in a furnace to be heat treated. Medium carbon steel welded chains respond better with heat treatment; providing twice the heat resistance.
However, even with higher heat resistance, one process is still often overlooked; tempering the barrel welds. As a result of the heat, the integrity of the components decrease making the chain wear quicker. It’s also important to note that poor weld fusion between the barrel and head sidebar can lead to premature failure. Even if the chain is at a proper load weight, the barrel’s reduced strength against bending will result in more sprocket contact. This contact can cause brittle fractures in heat affected areas of the sidebar which may lead to failure.