3M™ Glass Bubbles S38HS have a density of 0.38 g/cc and an isostatic crush strength of 5500 psi. The S Series glass bubbles have smaller particle sizes than the K Series.
The high strength of 3M's38HS glass bubbles (rated to 5500 psi) means they can survive both the rigorous demands of processing and the enormous water pressure at depth. In turn, their low thermal conductivity makes them ideal additives in insulation for pipelines and production risers helping to ensure that hot oil continues to flow to the surface, rather than cooling and slowing. Like all 3M glass bubbles, S38HS glass bubbles are virtually insoluble in water or oil.