Tensile Strengthis applied when you are talking about braking or shearing a piece of metal. Because all of the force you apply is over one specific spot on the plate you have to overcome the Tensile Strength to complete the job.Yield Strengthis applied when you are rolling a piece of metal. You are asking a little of every moment of movement.This is why when shearing or braking stainless steel or any other alloy where the tensile runs above 80,000 it requires a larger brake or shear to do the same thickness of plate while when rolling stainless steel, the size of the machine is very nearly the same. Example: 304 S.S. for instance has a tensile strength of 95,000 however the yeild is 35,000 making it about the same as mild steel.