Rick,
They look like Boeing numbers, try searching google with adding "BAC" to the start of the part number and removing the numbers on the end, see below. Material information will be in a Boeing SRM, chapter 51-40,
BACB30NR
BACB30NL
BACB30PN
BACB30LT
BACB30US
Also google, "eng-tips.com/viewthread.cfm?qid=124385".
Last edited by carlton; 21st December 2017 at 04:02.