6061-T5 and 6061-T6 aluminum sections are manufactured and certified to the same strength specifications. The only differences is a slight variation on the tempering process.
Bottom line is that you can use either one for you KR, they are of equal strength. For those who love to read about such details , I refer you to http://extranet.rina.org/rina_rules/rina_rules_2003/RINA%20RULES/PartDChap03 Sect02.pdf ,Tables 6 and 7 may be of particular interest. For the rest of you guys and gals......get back to work on the KR and have a GOOD DAY. Brant Hollensbe Des Moines Ia.
