Chainsaw

Chainsaw oil, or bar and chain oil, lubricates the guide bar, chain and drive sprocket of chainsaws and forestry cutting equipment.

The chain runs at high speed around a sharp radius, which throws oil off aggressively, so the defining property of a bar oil is tackiness. Tackifier additives make the oil stringy and cling to the bar rail and chain links long enough to reach the cutting zone instead of flying off at the nose. Good bar oil also cools the chain, flushes sawdust out of the bar groove and protects against rust on equipment that stands between jobs.

Using old engine oil as a substitute is a false economy: it lacks the tackifier, is thrown off immediately, and leads to rapid bar and chain wear. Check the oiler is feeding before each session and keep the bar groove clear.