Stainless Bolts > 1.5" Diameter for Section 8

[ConstantEffort]

What commercially available bolts are appropriate for a 18" CL600 manway on an ASME Section VIII Div 1 vessel with an MDMT of -200F? MDMT of -150F?

The vessel is 304SS. 18" CL600 flanges call for 1.625" diam bolts.

SA193-B8 Class 1 bolts are restricted to CL150 flanges per ASME B16.5.

SA193 B8 Class 2 bolts are restricted to 1.5" diameter per ASME Section II Part D Table 3.

SA193 B8M2 (not B8M class 2) bolts seem to work technically, but none of my bolt suppliers have ever heard of it. They say most folks order "B8" and don't even specify Class 1 or Class 2.

 

[GenB]

You may have to contact bolts mfr. Try aircraft bolt suppliers or military ones. They deal with higher strength.