What is it about t-nuts that I don't understand?

I'm doing a build and usinf t-nuts for the first time because I
want a removable back and front for not only interior adjustments but
also possible replacement panels with a port cut in.

I have these things from Parts Express called Hurricane nuts.

The goal was to have these things in pairs on the frame and on the
removable back.

I got my corrent jole size drilled through both pieces and when I
got the t-nuts inserted and tried to screm them down they backed up
and loosened a joint. The joint is a small problem to fix and I'm working on the back to catch any of these mistakes before doing
the front.

In playing with the bolt and the t-nut, there seemed to be a stop
at the end of the nut in the machining.

I want the t-nut on the surface of the removable panel to use as
a magnet catch for a grille on the front side and a mated nut on the
frame to draw down around a seal on the frame that I'll fabricate.

This means that I was figuring on one bolt going through the first and the second drawing down tight to the frame.

Where has the logic or selection of parts gone wrong here?

Are you putting the t-nut on the correct side of the panels? I assume that you have furring strips along the sides of the fixed panels. The t-nuts go on the back (inside) of the furring strips. The best way to set a t-nut is to drill the hole (5/16" for a 1/4-20 t-nut). Place the t-nut in the hole from the back and run a hex-head bolt with a washer through the furring strip and the t-nut. Tighten down the bolt with a socket wrench until the t-nut is fully set. Remove the bolt and move on. In a pile furring strip, even MDF, you should not have any problem with the t-nut tearing out unless you severely over torque the mounting screws. Usually you will tear out the head of a Phillips screw way before the t-nut gives.

On note about mounting the t-nuts. Make sure that the prongs are straight. Sometimes the prongs will fold up under the t-nut rather than bite into the wood.

Bob

_Now_ he tells me.

Well this project is a 'mule' a test box of a line array so I am
using up things I have to do the build.

And yes local hardware store has the real kind of t-nuts.

On looking more closely at what was happening, when using 2 of the
hurricane nuts when one would tighten down it would draw the
second one out. So bolting into one of these worked ok for this
job.

The treatment is not what I wanted though. I wanted use up those
hurricane nuts and dump the rest.

Bob

The goal was to have a flush flat metal surface to attach a grille
with magnets on it. The surface t-nuts would then be masked
when the grilles were attached.

Only other option I could think of are fender washers. But those
done sit flush either. The hurricane nuts and t-nuts in general
have a dimple which would allow a flathead screw to be flush. At least
that's the way they look.

I only use threaded inserts now. Get them at McMaster-Carr. They thread into the hole with a hex driver and stay put. Even when there's almost no "meat" between the hole and the speaker cut-out. Be sure and get them "with flange" or you'll run them right back out when you tighten down the bolt. Don't ask me how I know that!

They come in any thread size you could want in quantities of 50 or 100 for a few dollars.

The only way to fly.

• McMaster-Carr

Of course, these go on the front of the panel, whereas t-nuts go on the back. This fine for mounting drivers, but if you are mounting panels to furring strips, the flange will cause an air gap. You will need to either use a gasket or countersink the flange. When I have used this type of insert, I use the unflanged, drill the clearance hole for the bolt, then redrill for the insert shank to the exact depth required. I have never had a problem pushing the insert through the furring strip.

Personally, I prefer the t-nut. As long as I take reasonable care to set the t-nut prior to use, making sure that the prongs haven't folded up under the flange, I've not had a problem with tear-outs. Of course, if you must torque the bolt down with a 1/2" drive t-bar....

Bob

I use my cordless with some hex keys I cut the 'L' off of to drive the 1/4-20 or 10-24 cap head bolts on a fairly low torque setting. Still, there always seems to be at least one hole close enough to the edge of the cut-out that it works loose and then you feel the bolt turning and turning to no purpose! Which also destroys the edge and precludes fixing a new T-nut w/o filling and re-drilling.

Next time you tire of installing one more g-d driver think how it helps you maintain your edge:)

Yes, I have the stuff to countersink and have done that for a tnut
but ran into the backing out probelm using one forward and one
backward. These would not draw down.

A fender washer has nothing on it to give a flush mount.

I would use those socket things made of plastic but I had a bad
experience with them. One time I had a set of kit speakers
and the the holes must have been drilled incorrectly and those
plastic inserts did not fit properly. So I wanted to use a
surface technique to avoid the headaches.