OK so no confirmation about odd 1/2-18 thread, so I am forced to use logic because I have reached the end of the internet. The 53-811 is 1/2-14 MNPT and the vendors errored and have all copied each other or their supplier gave them the wrong thread designation.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
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