From Newsgroup: rec.crafts.metalworking
"Bob La Londe" wrote in message news:119jtb6$jpru$
1@dont-email.me...
On 9/30/2026 4:15 AM, Jim Wilkins wrote:
The rivnuts ...
There are two styles of tools I am familiar with for setting rivet nuts.
One that operates like a pop rivet tool, but it incorporates a
threaded mandrel. Of those there ARE two sub types. A regular right
angle fist grip tool of which most of us are familiar and a compound
crimp tool with leverage more like a bolt cutter.
The other is simpler, may be cheaper (except at an industrial bolt
supplier), and can be shop made. It is basically a GR8 bolt, a heavy
washer, and a clearance fit hex fitting with a coarse knurl more like
the bucking spikes on a chainsaw. You use a wrench on the hex with the spikes/knurl against the rivet nut, and tighten the bolt with a suitable wrench, socket, impact, or whatever. When the rivet nut is compressed
in place you just back out the bolt.
I expect that one of these tools may work better than the others for
your use. Some type or retaining compound might help. I don't know. I
would also suggest if you are still enamored of the idea of rivet nuts,
check to see if there are flush head countersunk versions available.
If a recessed or counter sunk head rivet nut is available some sort of
dimple die might just be the ticket to make everything work the way you
want.
Depending on how you punch the hole and dimple the sheet metal you may
also be able to create increased engagement surface for knurling on the
rivet nut itself.
--
Bob La Londe
CNC Molds N Stuff
---------------------------------
The Hardell tool is of the bolt cutter handle type which initially sets the rivnut without rotating it. I used my shop made bolt and wrench tool afterwards to pull the rivnut tighter, until I felt it bottom out. The
initial set and the friction of the stationary sleeve bushing against the
head were enough to keep the knurled stainless rivnut from turning from
thread friction.
In this case the patch doesn't need to fit flush, a drainage gap may be
better than sealing in high speed tire spray, which the original box channel design appears to have done on the V shaped and spotwelded bottom edge. I considered making a screw-together die set to form a shallow well around the rivnut head, but don't think it's appropriate or necessary on curved
surfaces that it will distort, and 18 gauge galvy steel is difficult to
simply shear or bend with a hammer. I've made such die sets for easier tasks like setting brass grommets in hanging tarps.
A more adjustable approach would be to fold the outer edges of the patch
down to form a seal with some spring. I've found that with curved metal I
need each forming operation to solve one problem without worsening another elsewhere.
Everything finally fits. I took it apart and sprayed LPS-3 inside the remaining box channel. The factory paint is still intact on exposed areas
that I sprayed 20+ years ago.
Does anyone else take auto body repair to this level? I can buy repair
panels for my 91 Ranger but not this 2000 Honda. I made the Ranger floor repair only because the available floor panel has the same drain hole where mine rusted around the rubber plug.
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