Unit daSt decastokes Kinematic Viscosity The decastokes (daSt) is a unit used to represent kinematic viscosity in the field of fluid mechanics. Viscosity is the measure of a fluid's resistance to flow or deform due to applied force or external stress. Kinematic viscosity (ʋ) is the ratio of dynamic viscosity (μ) to fluid density (ρ), and it is often used to describe the flow characteristics of a fluid. The primary unit for kinematic viscosity is the stokes (St), named after the Irish mathematician George Gabriel Stokes. One decastokes is equal to 10 stokes, so 1 daSt = 10 St. To give you a better understanding, the smaller the kinematic viscosity, the lower the resistance to flow or "thinness" of a fluid, and the larger the kinematic viscosity, the higher the resistance to flow or "thickness" of a fluid. Common fluids like water and air have relatively low kinematic viscosities, whereas honey and motor oil have higher kinematic viscosities. In summary, the decastokes (daSt) is a unit used to represent kinematic viscosity in the field of fluid mechanics, helping to describe the flow characteristics and internal resistance to flow of a fluid.