Answer) In comparison to rubbers and plastics, urethane has much better sound damping properties. The more rigid urethane is now part of the gears in a number of mechanical products where the engineers require sound to be as minimum as possible. On the other hand, soft urethanes are used to replace rubbers in machines to improve sound damping along with vibration. When urethane is molded straight to the metal inserts, then outstanding bonds are obtained. Thus, you can be sure of one thing, it is easily attachable to metal and other materials by a simple press fitting, cementing, and chemical bonding with the use of bosses and studs.