A brick having a low thermal conductivity and used as a backing for the more dense refractory brick.
NSN 6130-01-623-2496
NSN 5935-01-205-1040
NSN 7035-01-269-4152
NSN 5960-00-423-7842
NSN 4140-00-719-5654
NSN 6130-01-503-5849
NSN 5855-01-598-2062
NSN 5895-01-565-3960
NSN 6320-01-132-2746
NSN 6610-00-186-9180
NSN 5950-01-582-4738
NSN 5895-01-096-8982