Most accidents involving a chainsaw involve a kickback. It occurs when the bar or chain catches a foreign object while cutting, causing the saw to pivot. This can also happen if a person suddenly touches the top of the saw (as happens when bucking timber), or when the chain is pinched by a large piece of wood (such as an ax). To prevent a kickback, the operator must first consider how the saw will affect the material in question.
In order to avoid this kind of incident, it is necessary to know how to prevent chainsaw kickback. The most common cause is nicking the upper nose of the saw. Usually, the more the saw catches on something, the more violent the kickback will be. If the bar catches on a small piece of wood, it will result in a kickback. Luckily, most saws have built-in safety features, such as a “kickback danger zone” (90 deg angle at the top of the guide bar).
One way to avoid a chainsaw kickback is to be careful. The saw’s guide bar should never touch the guide bar’s upper tip. This can lead to a rotational kickback. When a piece of wood is struck by the guide bar, the entire saw can flip back. Then, when the chain hits a solid object, the whole thing will flip back and the operator will lose control of the saw.