Table 1A Asme Section II Part D

I would imagine that is the temperature at which the metal becomes unreliable.ie: either starts to melt or below temp for structural integrity...

You might not have the latest standards, as they change from time to time....

No...use the higher temp...

There is no term "exact" in designing. You got to deal with factor of safety to cope with deviation from the "exact" value and uncertainty.

Values used are derived from empirical method- this means an actual measurements of maximum allowable stress on samples tested.

I do not think ASME would put information on their standard which is unreliable for use . Read and read directions or procedures, most graphs and tables goes with empirical formula and direction, you could use to get maximum allowable stress.

I thought the table above from ASME Sec II part D was used for calculating the allowable stress in table 1A. But if it's not then what is the table 1-100 supposed to be used for?

I will not be baited and drawn into a rhetorical debate on this day! Therefore I regard the table itself as being superfluous to the answer.

So, for General Notes of table 1A" The stress values in this Table may be interpolated to determine values for intermediate temperatures. i do not directly answer the question re: 617 F (since I am ignoring the table), but the statement about stress values and interpolation gives the clue. When the values may be so interpolated, it becomes clear that the values must be not only be variable, but also linear.Make sense? Now, prepare to draw a atraight -line graph, leaving sufficient space on an axis to plot your 617 F. Report back and tell us what result you achieved. Do not tell us you can't plot the graph! There are members of this forum waiting in ambush for such an admission to appear in writing!