Hello Everyone,

I am trying to determine if I am able to use a 1/4" backing strip made of A-36 that remains in place without impact testing.

The A-36 backing strip meets all requirements of UCS-5(b)(2)(-b), except that assigning it to curve A, it would be above my MDMT (0F).

However, per UCS-66(h), no impact testing is required for materials assigned to curve A not exceeding a thickness of 1/4" when the MDMT is at or above -20F

My question is, does not requiring impact testing per UCS-66(h) imply that the material satisfies the requirements UCS-5(b)(2)(-b) assuming UCS-5(b)(2)(-b)(-1) and (-2) are also satisfied?

My initial impression is that UCS-5(b)(2)(-b) would need to be satisfied regardless of the UCS-66(h) exemption because it only references the Figure UCS-66 and not UCS-66 itself, but I am not sure.

Any help would be greatly appreciated.

Thanks,
John