I am told that how to count broken glass beads has become an audit issue. I’m not surprised – I have been privately wondering for a few years whether the count is to be(a) the number of original particles fractured or (b) the number of pieces resulting from the fracture.
Most specs have copied the ~10% broken limit for cast shot – same numbers for equivalent sizes, excluding only the smallest beads – and not addressing the issue above. Only AMS 2430 implies (a) by saying “10% of beads are broken”.
My opinion is that glass bead fracture counting should be deleted from all specs – and not just because of (a) vs (b). When a cast shot particle fractures we worry about a sharp edged particle of at least ½ original mass causing surface damage. If a glass bead fractures the myriad of sharp particles have little mass with which to do damage.
