Cribbing is often used in the repair of heavy equipment or farm equipment. Subassemblies that have been disconnected are supported by cribbing until reassembly. In such work, cribbing is often safer than jack stands because it is less likely to tip over. And if the metal parts bite into the wood, this helps to keep sliding from happening. These factors are especially true in field repairs, because most ground is not perfectly level and hard, like a concrete garage floor would be. Even on concrete, cribbing is often preferred.