i just looked up the spec ... NAS1242 are 1/64" over the nominal size (the 1/8" rivet is 9/64"). you need the spec (commercial property) but there really isn't much more in it ... they come in the range of common rivet materials (AD,D,DD) but no strengths etc (not even hole drill sizes for installation) ... your procurment people should be able to get more info. technically, substitution would be "passed -by-inspection" ... don't count on these guys being stronger, but certainly they are as strong as the original B/P rivet.