1.1 ,This specification covers aluminum oxide (alumina) powder in two classes of particle size, two chemical grades, and two levels of acidity, for use as an insulating coating or as an ingredient of ceramic mixtures for components of electronic devices as follows:
1.1.1 ,Particle Sizes:
1.1.1.1 ,Class A—,Particle size No. 500 nominal mesh (nominal average particle size ,= ,24.3 μ,m).