The blacksmith of Guédelon is hot working a piece of metal recognizable by its fire color on the anvil of the forge of the construction site of the medieval castle. His goal is to give it its final shape by stretching it, flattening it with a striking hammer, bending it on the horns of the anvil, cutting it, or welding it. The blacksmith holds the workpiece with his left hand with a flat pincer and reserves the strength and precision of his right hand for the use of the striking hammer.