Metal-Clad Fire Door 2 : A door with a metal-covered wood core, or stiles and rails and insulated panels covered with 24 gage or lighter steel. See: Kalamein
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}