A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 5930-00-597-5064
NSN 5925-01-062-7973
NSN 5835-00-463-6699
NSN 5930-01-565-2353
NSN 5950-00-627-1233
NSN 7035-00-529-3128
NSN 6150-01-230-3344
NSN 5925-01-432-1698
NSN 5930-00-297-8848
NSN 5895-01-231-9519
NSN 5835-01-232-1226
NSN 5925-01-480-0730