Looking at the data sheets, Tensile strength is listed as greater than yield strength. At least on Ultrat and PETG, maybe the others as well. For example on PETG, "Tensile Strength at Yield" is listed as 7252 PSI while "Tensile Strength at Break" is listed as 4264 PSI.
Something lost in translation? Never seen a material that breaks before it yields :) .
The elongation figures seem right though.
The values are correct. Please note that material is stronger when you stretch it before it yields.
After you pass yield strength value the material sample is getting longer and longer (it is called necking) and finally it brakes. The force needed to break the sample is smaller than to pass the yield strength.
Below you will find a stress - strain curve for a polymer:
http://blog.capinc.com/wp-content/uploads/2013/09/Material-Properties-for-Simulation3.jpg
OK. Can't say that I have ever seen it listed that way. The necking would reduce the area, is that accounted for in the quoted Tensile at break? Or the figures are from the original cross section prior to necking? In other words is the material getting weaker as it stretches, or simply the cross section is shrinking? Kind of an academic question I guess, if I hang a 6100 lbs weight on 1 sq in of Ultrat, it will not just yield, it will break.
