In Army machinist school we were never taught that there was a right component to tighten. Captive nuts that are truly captive—welded to the material part—have to be very precisely aligned. Plus not everyone has a way of tacking down a nut without screwing it up. The other way is to make a sheet metal cage out of an X of steel that captures the nut but let’s the nut move around enough to engage a bolt entering at an imperfect angle or position. 

And then there are rivnuts. The sets with the big pliers are very expensive but lately I have seen them with small wrench operated systems. 

But another option for you is to just take the part you make to a racing shop and see what they can do for you without buying and experimenting with a bunch of stuff. 

Jim

Sent from my iPhone

> On Oct 12, 2018, at 2:41 PM, Neil N <musomuso@GMAIL.COM> wrote:
> 
> Hi all.
> 
> Since it's Friday, and there's so little list activity....    < grin >
> 
> Application: custom muffler bracket mounted to a VW I4 gas engine in a Vanagon.
> 
> From a design standpoint, for parts using nut & bolt fasteners, since
> one tightens the nut to the bolt, are captive nuts more or less a
> "last resort" in terms of design?
> 
> With captive nuts, I guess that since the nut wouldn't have a washer,
> maybe tightening the bolt to the nut still provides a proper union?
> 
> I'm sure the bracket I'm making won't come loose (cracks due to design
> not withstanding LOL) so this is more out of curiosity than anything.
> Once again though, I'm reminded of just how much skill it takes to be
> a real fabricator.  LOL.
> 
> Neil.
> 
> 
> --
> Neil n
> 
> Blog: Vanagons, Westfalia, general <http://tubaneil.blogspot.ca>
> 
> 1988 Westy Images <https://picasaweb.google.com/musomuso/New1988Westy>
> 
> 1981 Westfalia "Jaco" Images, technical <http://tubaneil.googlepages.com/>
> 
> Vanagon-Bus VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>