Main Question or Discussion Point
My industry (tubular steel poles) standardly uses A572, Gr65 and A871, Gr65 for shaft design with the designs taken to the minimum ASTM defined Yield and using loading factors in the design. The A572 specification has for years listed all grades as "Yield Point". The A871 specificaion (which is relatively new) lists "Yield Strength" with a note indicating the use of the 0.2% offset method. I recently have recently seen the stress-strain curve of a test sample for A871 and it does reflect the graphical representation of the 0.2% offset versus the "yield point" style. This also reflects full scale testing results I have recently seen where the test structure DID NOT return to zero after taking all loading off. My question (finally): is the A572, Gr 65 REALLY "Yield Point" and not 0.2% offset? My industry has the expectation that structures will behave elastically through the Yield Point specified. I am suspicious that this is true. Can anyone clarify this for me? Thank you.