Stripped (nearly) threads in the frame. Now what?

[Brian E.]

My car's larger inner splash shield is secured to the frame by 4 hex head screws and one of those threads (in the frame) are too loose to adequately tighten this screw. How does one properly fix this? Is there a nut sert with sheet metal threads? What are my options? Please tell me what you / others have done?
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Note: I'm not interested in wrapping a copper wire around the threads of the screw because I'm hoping for a more proper fix.
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The car is a 67 coupe.
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[Curt R.]

I have used something called a Riv-Nut which GM used on shifter tunnels and areas that were hard to tap properly, you simply push them in and they expand once the bolt is tightened down. Simple, easy and secure!

[Tim G.]

Brian, I'm sure there are better ways, but I coat the screw in JB Weld and put it in as best I can allowing it to dry. I've used it on those very same screws, and it has worked fine.

[David H.]

Brian

Rivet-Nut would be my choice as well. Several different manufacturers, so expect several different spellings of the type.

They will be accompanied by rather expensive installation tools. I've included a youtube link below for installation with simple inexpensive tools.

They work well in non-critical situations, but you want to do a good job installing them. If too loose, then this nut will spin and you get to do it over.

ALSO rivet-nuts come in a WIDE range of sizes, HOWEVER everyone I've seen, or used, come in typical metric or imperial course/fine thread. Not as in your example of self-tapping/coarse screws.

Dave

https://www.youtube.com/watch?v=R5mXTGUO82g

[Terry M.]

Brian, if you want a permanent fix using original fasteners you may need to remove the shield and weld the hole shut or nearly shut, redrill and then install the shield. No one will ever see the frame once the shield is in place.

[Greg K.]

Terry's suggestion is probably the best if you want to use the same size screw. Your other option is to re-tap the hole to the next size bigger thread. Not sure you can find a sheet metal thread tap though. Or you could practice using a self-tapping screw (next size bigger) on a separate piece of steel, same thickness, with same size hole as the frame. Good luck.

[Brad H.]

Looking at your photo, I question if the issue is the frame hole is to large, or the threads missing on the screw at the critical point of tightening? Appears your screw is damaged and may not be holding tight because there is no thread left to hold it tight at its full installation. Possible that a new correct undamaged screw solves your problem without modifying your frame hole?

JMHO

brad

[Dale E.]

Agree with Brad, looks like screw is damaged

[Brian E.]

I have a couple of new screws coming so we'll see what happens when I get them. Thanks.

[Karl L.]

Use care when tightening the new bolts and don't overdo. Just snug with a 1/4" drive ratchet is enough.
TIG weld the loose hole(s) (Heliarc) is an option if you're handy with a welder.