top sketch is looking down on your wooden table, 4 slots cut to match the spacing of the steel table slots.

bottom is a side view, you slide a bolt into the steel table slot, and the wood table slot, securing with a washer and nut (recessed below table top).

got it?

27 minutes ago, DAB said:

got it?

This helps a lot! Sort of a combination of recessing a bolt with a "side" attachment. Thank you!

little better sketch of the steel table and wood table interface i'm trying to describe.

i'd make the wood table about 1-1/2" thick (maybe two layers of plywood and a layer of 1/2" MDF), and then using a Forstner bit, create a recess for the bolt/washer/nut you can access from top, and have it still below the top, so it won't interfere with whatever you are drilling.

you can create the slot in the wood table with a drill (little bigger than the bolt diameter), and either a bandsaw, or just a handsaw, then slide the bottom (in this view) bolt and washer into the steel table slot and the wood table slot at the same time, and once in place, tighten the nut. doesn't have to be overly tightened, it's just holding the wood in place.

better?

I'll need to get some different bolts and washers if I go this route. I checked a T-bolt from a t-track hardware set I got years ago in a holiday sale and the toilet set I picked up this morning, and neither are the appropriate size, and no washers on hand that would work.

Was hoping one of these would work, but too small. Will need to do some better measuring and planning.

Right now I have the two 1/2 inch plywood glued up - and I do have more of that so can add another layer. That would be a good thickness so I could have a cutout for a replaceable piece to serve as sacrificial support.

have fun storming the castle!! or shopping for nuts, bolts, washers.....but the castle part sounds fun.....

3 hours ago, BB1 said:

I'll need to get some different bolts and washers if I go this route. I checked a T-bolt from a t-track hardware set I got years ago in a holiday sale and the toilet set I picked up this morning, and neither are the appropriate size, and no washers on hand that would work.

Was hoping one of these would work, but too small. Will need to do some better measuring and planning.

Right now I have the two 1/2 inch plywood glued up - and I do have more of that so can add another layer. That would be a good thickness so I could have a cutout for a replaceable piece to serve as sacrificial support.

How about cutting a small block of wood to fit the table slots and then embed the bolt upright though the bottom? And then go with DAB's plan for the rest of it.

The blocks don't even need to be the full thickness of the slot. Full thickness might be difficult to get into the slots.

This is what I have done when the slot is too wide for the closet bolt

Take a large washer and grind off 2 sides to fit in the slot, drop it over a bolt and slide the pair into the opening.

2 hours ago, Headhunter said:

How about cutting a small block of wood to fit the table slots and then embed the bolt upright though the bottom?

Well, that's a great idea. I looked through my random hardware storage with no luck. Wouldn't have come up with this - good tip.

2 hours ago, lew said:

Take a large washer and grind off 2 sides to fit in the slot, drop it over a bolt and slide the pair into the opening.

Another good tip. And I might have an oversized washer that might work if trimmed.

Appreciate the responses. I'm working finishing a floor transition and some other house update projects, but hope to get back to working on this "soon." Knowing how long shop projects take me to complete, that could be this week or in a month...or more. 😁

This is something you would have to order but is not expensive. It is a flat oblong piece which is threaded , then I would use a bolt with recessed hex to screw it in from the top. There are also heavier versions of this nut. This would be stronger . You will have to right click these links

Economy centered t Nuts

These are heavy and come in many widths and heights . make measurements before you order.

Threaded T Slot nut

Edited Wednesday at 04:12 AM2 days by Gerald

T-nuts like the ones JWD and Gerald suggested are probably the best way to attach anything to a t-slotted table. For your application you could make some out of wood and attach the top with plain wood screws countersunk in the top.

Just measure the t slot dimensions in the table and run off a length of stock on a table saw to match. Then cut off as many as you need.

Edited Wednesday at 12:43 PM2 days by Zack

I'm afraid I can't follow Gerald's links for some reason

I've used weld nuts in small (Kreg) T slots before:

https://www.mcmaster.com/products/slot-nuts/weld-nuts-3~/

Easy to grind a bit off on a bench grinder if they are a hair oversize.

The big advantage of those machinist's T nuts is that they don't wiggle around in the slot (or they shouldn't if everything is sized correctly) and that makes them very easy to line up with your bolt - you don't have the problem of the nut moving on you as you try to start the bolt. The downside in this application is going to be finding a flat head screw that is large enough for what is likely a 3/8" or 10mm threaded hole! I hadn't thought of that when I suggested it initially.

I like Zack's suggestion of making a similar version out of wood. I would then use a flanged weld nut epoxied into it and do the countersunk flatheads. 1/4-20 is a good size to use, probably one of the most commonly available screw pitches around in the US. Like the flange bolts, every hardware store has 1/4-20's! A lot of them still have taps and dies in the common sizes too.

In a pinch, you could even tap the wooden block for the machine thread you want to use. I've done that, works fine. You can't cinch it down like with steel nuts, but it works in many cases.

Those links didn't work for me, either.

Unfortunately, I wasn't able to access those links either. Will need to take some time to read through all the new posts. Greatly appreciate all the suggestions and information!

For today, got my last floor transition in place.

Now to an update to the "landing" in front of our fireplace. I keep telling myself that it is "nice" to be able to work through these home projects rather than paying to have them addressed. Right?!? 🤔

Not sure if this is exactly where @Gerald was referencing-

Framing Tech

Economy T-Slot Nuts | Framing Tech

Economy T-slot nuts offer a budget-friendly solution for securing components in T-slot aluminum framing systems. Ideal for light-duty applications, prototypes, or projects where cost savings are a pri

https://www.mcmaster.com/products/t-slot-nuts/

some nice fender washers will suffice, something that fits into the steel table slot.

The two references to economy nuts were in the first reference. The second in a much beefier nut with wedge shaped top and other configurations. I had much trouble with the links and replaced them twice.

https://www.amazon.com/Zadery-Applicable-Aluminum-Extrusion-16/dp/B0D14QZPN4/ref=sr_1_3?crid=MRJ1941D8GBU&dib=eyJ2IjoiMSJ9.m2zum2Jp1BpphOHQnzq94THBCVOj7YsgxgCr9h_ioEJ1BIooaDYy_lKGE4tsn107nSxRrtsKwydMuQWl0sJppiHxfIAQKKkcJsryjppSG0rBmCJ8YKwbTK6p8-0-KlXJN3pWWzkogawOAwTsbNF1qck-Qft2YpJgZHYk7u4snpwdEHKo-m3v7Ir2cf4oKXhFpSTojZl122KujmbSPQeEGEwPh2tdSlgPHAkJre4yC28.ke5JCHqs-cZLFGJMhoAHP7id-Pk-z_TxBuFHSlkBnTI&dib_tag=se&keywords=t%2Bnuts%2B5%2F16&qid=1788464206&sprefix=t%2Bnuts%2Caps%2C245&sr=8-3&th=1

Missed getting on yesterday to replace. Links will not work just copy and paste the above. There are many designs of this type nut .

Edited yesterday at 07:45 PM1 day by Gerald