How to install screws and t-nuts

[qguy]

I have searched high and low (maybe not high or low enough) but cant seem to find the answer to this.

When drillling holes for the screw, do you let the teeth of the screw bite into the wood or the hole should large enough to let the screw slide freely into the hole and then bite into the t-nut.

Application is for a 15 inch SEALED sub, hence the idea of having a tight fit for the screw.

[richie00boy]

The wood hole is to allow the screw to pass freely. If you let the wood bind you may end up with difficulty getting the screw to engage with the t-nut when it hits it, as the threads could be misaligned.

[AndrewT]

the Tnut diameter determines the diameter of the hole in the back of the panel.
You could, in fairly thick panels, drill two diameters. One just deep enough for the Tnut and the other drilled all the way through for the bolt.

[AndrewT]

What the heck is that noise?

Oh it's two Chinooks passing overhead. Amplifier is OK !

[Cal Weldon]

Originally Posted by AndrewT

the Tnut diameter determines the diameter of the hole in the back of the panel.

Yes.

Originally Posted by AndrewT

You could, in fairly thick panels, drill two diameters. One just deep enough for the Tnut and the other drilled all the way through for the bolt.

I think this is an unnecessary step. What might be the advantage?

[Michael Bean]

No need to worry about leakage, t-nut flange and screw threads will seal things up nicly when it's properly torqued down.

Mike

[planet10]

With a t-nut i always pull the nut into place with a sacrifical bolt & a washer. Slow & steady to ensure it is seated. Nothing worse that a t-nut coming loose inside the box with the driver in place.

One of the reasons we use inserts instead of t-nuts.

dave

[Cal Weldon]

Put a dab of construction adhesive on the flange when you torque it in. But yes, threaded inserts are nice. Do use a jig like this?

http://www.woodsmith.com/files/issue...sed-panels.pdf

[AndrewT]

Originally Posted by Michael Bean

No need to worry about leakage, t-nut flange and screw threads will seal things up nicely when it's properly torqued down.

the thread form of the nut and bolt always leaves a small gap between the tip of the male thread and the bottom of the female thread.
This is usually achieved by truncating the tip of the male thread.
There is an exception BSP pipe threads where the male and female thread are made to be close replica of each other so that a gas tight joint can be made usually with some filler in the threaded joint. I think NSP also fall into this gas tight category.

[sofaspud]

The method I use is to drill a hole according to the diameter of the T-nut, then I use a C-clamp to firmly seat the T-nut into the hole. A washer or coin opposite the T-nut can protect the wood from the C-clamp. Works like a charm.