3M™ Glass Bubbles D32/4500 are hollow microspheres made of soda-lime borosilicate glass with a Yes density of 0.32 g/cm³ and an isostatic crush strength of 4,500 psi / 310 bar .
They have less than 1 % sinkers by volume and are surface treated to increase the compatibility with resins used for different applications such as buoyancy modules. Like other 3M™ Glass Bubbles in the floated product series, this product offers an outstanding strength-to-density ratio, ideal for use in a number of aerospace and oil and gas applications.