Density Cube Sets (LSE) Here are handy, low-cost sets of one-inch cubes that can be used in many experiments. What makes them unusual? They offer an array of materials we actually use today. Learn about density, mass, volume, buoynacy, specific gravity and flotation while experimenting with real-world building materials. Grades 6-8 and up. Our Density Cube Sets have long been popular because they meet curriculum standards. At a teacher's suggestion, we've just improved upon our largest set. We've added two new cubes (for a total of twelve): polypropylene and lignum vitae (ironwood).The twelve piece set also includes a handy storage case. Polypropylene floats in water, although because it is dense plastic, your students would expect it to sink. Lignum Vitae sinks in water, but because it is wood, your students would expect it to float. Lignum Vitae is three times harder than oak. One of the hardest and heaviest woods in the world, it has a specific gravity of 1.05 and a density of 77-82 lbs/ft3. 30-152 Density Cubes Set of 12 includes: Lignum Vitae, Polypropylene, Aluminum, Oak, Steel, Nylon, Brass, Pine, Copper, Poplar, Acrylic, PVC, Instructions, and Storage Case. 30-161 Density Cubes Set of 10 includes: Aluminum, Oak, Steel, Nylon, Brass, Pine, Copper, Poplar, Acrylic, PVC, Instructions. 30-020 Density Cubes Set of 4 with Hooks includes: Aluminum, Steel, Zinc, Brass, Instructions. 30-005 Density Cubes Set of 4 without Hooks includes: Aluminum, Steel, Copper, Brass, Instructions. Qty :