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[Dave R]

Maybe this will help.

A circle with a radius of the ring.

Extrude with Push/Pull to the required thickness.

Use Offset first to delineate the radius of the post. Then draw a line for the flat.

Push/Pull to get rid of the waste.

Select the remainder of the offset edge and use Move/Copy to copy it to the opposite side. You could have used Offset on the other side as before but this is quick and easy, too.

Push/Pull the inner faces on both sides to make the post.