[Hobbiest]

Had the idea last night...instead of making some centering blocks out of MDF or whatever, just get the next size up pipe flange and drill and tap four holes toward the center! Steel threads hold a lot better, and its not like the things are really that expensive!

[AJ_Mac2001]

Nice Idea!!

Would have liked to have had that brain_art a month back when I was working up 16 pcs (ply versions) with a blunt holesaw. I think the smoke is just starting to clear in my shop

[xairflyer]

Does sound like a very good idea, what thickness would the wall of the flange be that you'd be tapping ?

[Hobbiest]

I think that the flanges are 3/16". With a fine thread bolt there should be plenty of threads in the piece. It could even be backed up with a nut on either side if the ID of the flange is big enough. jam nuts on the outside would be a good idea in either case.

[pack rat]

You could add a short nipple or a half of one and tread that . Schedule 80 will also give you more thickness. Good idea.