Yield stress point

(Link) “Minimum stress value applied to inital flow.” When the fluid is below this point, it displays the properties of being a solid or in that it isn’t flowing the way water might flow. When it’s above it, it’ll flow like a liquid. (Reference) In other words, this is the point we need to reach to get the fluid moving. We could measure this by saying something like, “It takes four taps on the table to get the ketchup out of that glass bottle.”