ksielongation length 4 u00d7 diameter 9 reduction of area 10 ______________________________________ ______________________________________tensile strength 175 ksiyield strength at 0 2 offset 140 ksielongation in 4d 8 reduction of area 12 ______________________________________ the following minimum values are measured in accordance with astm e21 on specimens heated to 1200 u00b0 u00b1 5 u00b0 f and held at heat for 20 minutes before testing ______________________________________tensile strength 135 ksiyield strength at 0 2 u00b0 offset 105 ksielongation in 4d 10 reduction of area 15 ______________________________________ mean linear thermal expansion should be no higher than 4 5 u00d7 10 6 in in u00b0 f from room temperature to 780 u00b0 f determined in accordance with astm e228 testing and specimen dimensional requirements shall conform to the requirements of astm e292 except as noted below a standard cylindrical combination smooth and notched or a separate notch specimen is maintained at 1000 u00b0 u00b1 5 u00b0 f while a load sufficient to produce an initial axial stress of 70 ksi is applied continuously the environment for testing should be controlled to temperatures in the range between 70 u00b0 to 80 u00b0 f at a relative humidity of at least 50 rupture in either the smooth or notch region of the specimens is permissible the specimens should not rupture in less than 32 hours grain size should be astm.