According to an unwritten carpenter's rule, a carpenter must never strike wood with metal. This is particularly the case with the handle of a tool, such as that of the wood chisel. When shaping a mortise, for example, a great deal of force is required to drive the chisel into the wood. Even a handle made of hardwood will not stand up to the repeated blows of a hammer. Therefore, the carpenter uses a mallet, made from hardwood, to drive the chisel or move a piece of wood whose surface he or she wants to work. The striking part of the mallet is made from a dense wood that resists splitting, i.e. a wood with twisted grain, such as elm or apple. Mallets come in various sizes and weights. The very largest require both hands to manipulate.
Older hammers were not fitted with claws, like their modern counterparts. Their size and weight varied. The heaviest version (1.5 kg) was used for driving boasting chisels. It was never used to strike metal (remember the unwritten rule), as wood is too soft to stand up under the force of a hammer's blows. Generally, hammers are used to drive in nails, while wooden pegs are set using mallets.
The larger of the two hammers was made by a local blacksmith, Joseph Gallopin from Maulers (Oise). The Dubois family often commissioned various tools from him.