Hex nut posts can be fixed to an optical table with M6 screws without the need for any holder. It can be easily tightened and used on the table with the 11 hex nut on it.
This non-magnetic 303 stainless steel base has a diameter of 12.7 mm. A frequent problem with short post is that the thumb of a pedestal holder is caught in the hole on the side of the post. To avoid this problem, these posts do not have this hole. Instead, the M4 threaded end of the post is a universal 11 mm hexagon to allow the user to provide extra leverage with a wrench when tightening assembled components.