It has been my experience that T & Y properties are the deciding factor when I’ve submitted similar proposals to the EOR.
These are actually CastConneX cast steel connections that will be CJP welded to the ends of HSS round 8.625 x .375 A500 B tubes.
I know there has been some discussion about adding the A958 spec. to the approved base metal groupings, because “the the chemistry of cast steel is similar to typical rolled steel.” (Exploring the Need to Include Cast Carbon Steels in Welding Procedure Specifications,” Welding Journal, October 2015, pp. 56-58).
Also,
https://www.castconnex.com/system/drive/files/uploads/000/000/002/original/ESR-3031_cast-connex-high-strength-connectors-code-listed.pdf?1460394327The parts are too thick for D1.3