I just discovered that in ASME II, SA-563 table 3 note (D) says SA-194 2H nuts are an acceptable equivalent (and they are good to down to -55°F). So, I'm going to use those.
When you use SA-354 BD studs, the ASME Section II says they shall be used with SA-563 DH nuts.
ASME VIII DIV.1 UCS-66 gives an impact exemption temperature of 20°F (-7°C) for the SA-354 BD studs but I cannot find the exemption temperature for the nuts.
Does anyone know where to find this?
The...