Page 29-21 step 1 has us bolt the roll bar bases to the fuselage. The hardware call-out is an AN4-7A bolt, one NAS-1149F0432P washer that is shown under the heat of the bolt, then through the material, and then an MS21042-4 locking nut. Should there be a washer between the nuts and the material? It just seems odd to me that there wouldn't be.