Chrome steel has a density of 7.9g/cc (used mostly for grinding leaves). Beads are sold in one pound bottles.Cat. No. 11079113c 1.3mm diaListed bead sizes are median (average) values. Because beads are sorted by sieves, bead size varies between +/-10% of a listed value.With either stainless steel or chrome steel beads, common polypropylene microvials will break if 'dry' grinding or cryo-grinding is attempted in our MiniBeadbeaters. In this case, our 2 ml stainless steel microvials with silicone rubber caps or our 2 ml XXTuff polypropylene screw cap microvials are recommended.