What is the term for the turned under edge or horizontal portion of the header of the casket cap?

The correct term for the turned under edge or horizontal portion of the header of the casket cap is "header flange." This term specifically refers to the part of the casket that extends horizontally, providing a finished look while also serving a functional purpose in the casket's structure. The header flange helps in attaching the casket cap to the body of the casket, contributing to the overall craftsmanship and integrity of the design. It is an essential component that underscores the importance of quality in casket construction, enhancing both aesthetic appeal and durability.

In contrast, the liner refers to the interior fabric that lines the inside of the casket, and the rim refers to the uppermost edge that outlines the opening of the casket. The cap edge typically describes the area where the casket cap meets the body, but it does not specifically denote the turned under edge feature. Each of these terms represents different parts of the casket, but "header flange" accurately describes the portion in question.