Allowable stress differences between product forms for the same grade

[beh188]

If you have a given material grade, for example 316 or 304 stainless, is it typical to expect the allowable stresses in the B&PVC to vary depending on the product form you select (bar, pipe, plate, forging)? 316 is probably a bad example because I am pretty sure the allowable stresses are the same independant of grade. However, for other materials would you expect the allowable stresses to vary depending on what grade you select? What drives these changes (grain structure, hardness, ect.)?

Thanks.

 

[SnTMan]

beh188, it is typical for allowables to vary with product form, just review Sec II, Part D. Additionally many austenitic stainless forms have a higher and a lower allowable, based on permanent deformation. Forgings have a higher and lower allowable based on thickness as well. So for austenitic forgings you might have four allowable ranges for one product form.

What drives the changes? Uhhh, metallurgy

Regards,

Mike