The materials covered by this specification are intended for use as damping fluids, transducer fluids, lubricants, heat transfer fluids, dielectric fluids, mold release agents, water repellents, hydraulic fluids and protective dressings and impregnants. Dimethyl polysiloxanes are not effective lubricants (steel against steel) at high loads. These fluids, particularly in the lower viscosities, tend to cause certain elastomers to shrink and harden. Consideration should be given to the type elastomer used when in contact with these fluids.