The problem: The stepped bar with a circular hole, shown in Figure P5.75, is made of annealed 18-8 stainless steel. The bar is 12-mm thick and will be subjected to an axial tensile load of P=70kN. The normal stress in the bar is not to exceed 150 MPa. To the nearest millimeter, determine (a) the maximum allowable hole diameter d. (b) the minimum allowable fillet radius r.Given figures: So let's talk about part a. I understand that K=σmax/σnom. D is given as a constant, so K seems to be a function which will vary with d. σnom is also a function which will vary with d Now if an actual formula were given for K in terms of d and D, we would have one equation and one unknown, and I would know how to solve for that. We just have a picture of the plot of K though. So how does one go about it? It seems the only way to do this is basically to just guess a d value, look up K, calculate σmax, and see how close you are to the 150MPa. Is it really just that? Or is there a better way to do this? Thanks in advance to anyone who can shed some light on this.