# Making a table: T-nuts OR threaded inserts?



## loninappleton (Jun 12, 2008)

I have had fair results with t-nuts as a way to secure a center leaf in a router table. Draw down works ok and helps with leveling but a little pressure when removing the screws drives the t-nut back out. T-nut draw down is done by inserting the thing from the opposite side.

Today I was experimenting with a threaded insert. It has thread outside and inside to match my bolts. So they screw in. I put these in the opposite side as well but it appears that they are drawing through the leaf as it is tightened. If they go in too far I'll not be able to get them out.

The only fix I've seen says to epoxy the inserts in place. There was no drive-in inserts available at the hardware store. The bolt size is pretty large at 1/4in. Pilot hole for the inserts is 3/8.


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## chrisexv6 (Apr 22, 2008)

Ive been thinking of trying to use something similar to the cam fasteners that come with a lot of pre-fabbed furniture.

It seems to me that the farther you screw the cam, the more pull it will have on the cam bolt. The question I have is how well the cam stays in place if not drawn down all the way. If the cam holds itself in place, you should be able to use cams and cam bolts to vary the amount of pull, and it will help level a table top.

If used in only the 4 corners of a top, they should be an easy way to bolt a top to a table.


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## loninappleton (Jun 12, 2008)

My table is crude out of necessity. I just don't understand enough of how those cam bolts work or even where to get them.

In thinking this through I should be using some sort of flat head Conformat bolts as well so as not to have to bore for a big bolt head.

Thanks for the reply. Maybe more discussion will bring up some more ideas.

I use what can be called 'sacrificial tops' that can be scraped and dinged and so on without much worry and for multiple uses.


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## jschaben (Jun 21, 2009)

Hi guys. Personally I'm not particularly overwhelmed by the cam lock things I see used in the cheapo furniture. I would be especially reluctant to use them on any shop item. I like the t-nuts myself and, while it is true they can be easily knocked loose especially if installed in manmade material. A little epoxy or poly adhesive usually handles that. 
Another alternative is to go with weld nuts w/holes. Not usually found in the big box stores and if you can find them there, they would likely be cost prohibitive if the project was very large. They are basically a t-nut but instead of prongs, have several small holes around the base you can use small screws to retain them. Here's a picture and a link:
McMaster-Carr


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## Mike Wingate (Apr 26, 2009)

I like T-nuts. I drill a 7mm hole in the worktop and make a wood handle with inset T-nut, that fits under the table, a longer bolt then holds the attachment with no pull through, and less chance of damaging the table. What about magnets?


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## loninappleton (Jun 12, 2008)

I can use the inserts and I know where to get the finer drive in ones at places like Parts Express which supplies speaker building materials. But shipping on a small item like that isn't worth it. Locally I've only seen the threaded outside threaded inside ones. I don't know how much action the inserts get with frequent draw down and bolt removal and if the glue mentioned actually secures them,


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## RJM (Apr 11, 2010)

loninappleton said:


> I can use the inserts and I know where to get the finer drive in ones at places like Parts Express which supplies speaker building materials. But shipping on a small item like that isn't worth it. Locally I've only seen the threaded outside threaded inside ones. I don't know how much action the inserts get with frequent draw down and bolt removal and if the glue mentioned actually secures them,


I don't like the threaded inserts you are talking about. They depend on the htreads for clamping load, they're hard to drive in straight, and they do tend to unscrew or screw in at times.

Instead, I like the "screw-on" (not "in") T-nuts like these: Screw-on T-nut. These are verey strong and go in easily. If you have enough edged distance, use these. Three #6 screws hold them on. A 1/16" deep counterbore made with a Forstner bit (1-1/4" dia for 5/16-18 t-nut) makes them flush with the surface. These cost a bit more but work really well. I have not found any smaller than 5/16-18.

If you cant get the screw-on t-nuts, then the "hammer-in" ones are also good (at least better than the screw-IN ones you're writing about). You can get these lots of places: "Hammer-in" t-nut. Amazon, McMaster-Carr and lots of other places sell them and they're relatively cheap.

I also found these: Hurricane Nuts. These are very simmilar to the weld-on nuts but they're made for wood. The manufacturer claims that the flutes hold really well against torquing. Amazon has size 8-32, 10-32 and 1/4-20 but Mcmaster-Carr also sells 10-24, 5/16-18, 3/8-16 and 1/2-13.


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## RJM (Apr 11, 2010)

McMaster Carr also has the Screw-On type for much less:  Screw-on T-nuts (McMaster-Carr)


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