The most significant feature difference between metal and
wood caskets lies in how the lid closes against the shell of the casket. In the majority of metal caskets, a rubber gasket is inserted and wrapped around the entire perimeter of the casket shell. When the lid of the casket is closed a sealing key is inserted on the exterior foot end of the casket and turned to provide a secure closure.
The gasket feature has been designed to prevent outside elements from entering the casket in the burial state. The gasketed seal in no way prevents or slows down the naturally occurring decomposition of the body.
The gasketed feature is exclusive to most metal caskets.
Wood caskets are not constructed with gaskets.