The most popular and widely used copper powder, produced by water atomization method followed by hydrogen reduction. Applications include production of copper compounds, catalyst in chemical formulations, abrasive wheels, carbon brushes, and more.HTS Code: 7406.10.0000 NMFC: 30743 CAS: 7440-50-8 Additional Description Product Details: Purity: 99.3% Apparent Density: 2.7 g/cc Nominal Mesh: -140 -325 mesh ratio > 50% Application: General purpose, brazing, chemical, electronics, paints, …Note: Pure copper powders do not show continuity or conductivity by a multimeter. I think there are two reasons for that. One is the low voltage used for the test. The other is lots of air and weak contacts between the particles. They will show conductivity with higher voltage, when they are compacted and when they are mixed with some oil or resin to form a paste.