Tee Slot Measuring

bushwacker

bushwacker

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Hiya everyone,
can any one give me a little bit of advice here please, I need to order a set of tee nuts for a pillar drill table and in the catalogue it says to order
6-8-10-12 m/m now then is this the dia of the thtread in the tee bolt nut or the size of the top portion of the nut or the size of the bottom portion of the nut. I can't mill any for my self as I don't have access to a milling machine and they are for work so I can only order from company approved suppliers. It does make it a little on the awkward side to say the least. I hope thtat I have explained it clearly, I'm not that good at that some times:nervous:
 
The T slots are measured across a flat section of the nut as far as I can recall. Unfortunately I can't recall if it is the top or bottom that the measurements are taken from. One of the smarter fellows will probably be along shortly and give us the correct answer and we can both learn a little something too. Sorry I cant be of any more help than that.

Bob
 
Tee nuts are measured by their thread size but Tee slots are measured by the nut that would fit in the throat size. So a Tee slot that measures for example 11 mm in the throat, (narrow section) and would be about 18 mm in the wider section, would be designated a 10 mm tee slot. However the Tee nut to suit would be 10 mm (nominally) across the narrower portion that fits the slot and would be tapped to take an 8 mm stud. so the Tee nut would be designated 8 mm to fit a 10 mm Tee slot. Neither component actually measuring what the designated size is!!!
Does that clear it up for you?:lmao:

Cheers Phil
 
A few months ago, I bought a Weiss VML30-D mill. The specs say 7/16 T-slots, so I bought one of those kits that have the 7/16" T-nuts, 3/8" studs, nuts, stepped stand-offs, and clamps. Been holding my vise since I bought the mill. So, I thought I would buy extra T-nuts. But they are larger in all dimensions except the hole - throat, headspace height and width. I can almost start the T-nut in the table but half-way in it is a no-go.

The larger nut fits the headspace fine - it is the throat I have a problem with. Now I am a Newb, but I am convinced it is the correct nut and the one from the kit is actually too small. What I noticed is the throat is not machined. It has some high spots and is painted with a thick coat of paint. I can take the big nut, invert it, and place it in the throat at most locations, but where there is a high "bump" in the casting or sometimes thickness of paint, it takes effort or will not go at all. That includes the area where I can slide it in 1/2 way and it stops dead - there is a high spot in the casting.

What can I do to solve this? Mill the edge of the slot? I'd have to take the table off and take it to a machine shop for that as the table will not travel far enough to mill to the ends. I could use an angle grinder with a Roll-Lock and gently take down the high spots...

Thoughts?

John
 
Damn Yankee said:
A few months ago, I bought a Weiss VML30-D mill. The specs say 7/16 T-slots, so I bought one of those kits that have the 7/16" T-nuts, 3/8" studs, nuts, stepped stand-offs, and clamps. Been holding my vise since I bought the mill. So, I thought I would buy extra T-nuts. But they are larger in all dimensions except the hole - throat, headspace height and width. I can almost start the T-nut in the table but half-way in it is a no-go.

The larger nut fits the headspace fine - it is the throat I have a problem with. Now I am a Newb, but I am convinced it is the correct nut and the one from the kit is actually too small. What I noticed is the throat is not machined. It has some high spots and is painted with a thick coat of paint. I can take the big nut, invert it, and place it in the throat at most locations, but where there is a high "bump" in the casting or sometimes thickness of paint, it takes effort or will not go at all. That includes the area where I can slide it in 1/2 way and it stops dead - there is a high spot in the casting.

What can I do to solve this? Mill the edge of the slot? I'd have to take the table off and take it to a machine shop for that as the table will not travel far enough to mill to the ends. I could use an angle grinder with a Roll-Lock and gently take down the high spots...

Thoughts?

John
Click to expand...
Machine the tee-nuts to match your table slots. Take off a little at a time (on both sides to keep it even!) and slide the nuts along the slot for fit. When you get it to slide freely, check your other slots! That one may not be the narrowest one. Once the tee-nut slides ok in all the slots, measure it, and machine the rest of them. It sounds like a bit of work, but after the first one, the rest go quickly.
 
Damn Yankee said:
What I noticed is the throat is not machined. It has some high spots and is painted with a thick coat of paint. I can take the big nut, invert it, and place it in the throat at most locations, but where there is a high "bump" in the casting or sometimes thickness of paint, it takes effort or will not go at all. That includes the area where I can slide it in 1/2 way and it stops dead - there is a high spot in the casting.

What can I do to solve this? Mill the edge of the slot? I'd have to take the table off and take it to a machine shop for that as the table will not travel far enough to mill to the ends. I could use an angle grinder with a Roll-Lock and gently take down the high spots...

Thoughts?

John
Click to expand...

WobblyHand said:
Machine the tee-nuts to match your table slots. Take off a little at a time (on both sides to keep it even!) and slide the nuts along the slot for fit. When you get it to slide freely, check your other slots! That one may not be the narrowest one. Once the tee-nut slides ok in all the slots, measure it, and machine the rest of them. It sounds like a bit of work, but after the first one, the rest go quickly.
Click to expand...

My two cents:

Step 1: remove the paint from the t-slots. A machine table shouldn't be painted.
Step 2: use a file to clean up any casting bumps and make the slot more-or-less parallel.
Step 3: once the slots are straight and clean, if the t-nuts still don't fit, mill the nuts.


I wouldn't go to the trouble and expense of having the table machined outside. But if it is a turret mill (like a Bridgeport), you can swing the turret and cover the entire table (takes two or three setups). Making all the slots exactly the same width, straight, and parallel to the table travel is definitely the best outcome but it can be significant work. And not possible on a mill without a turret.
 
Tee nuts, aka tee slot nuts, are specified by the distance across the flats of the neck of the nut and the thread size. They come in Imperial and metric sizes. The table slot is usually slightly larger than nominal size and the nut slightly smaller.

MSC UK is an industrial supplier in the UK. https://www.mscdirect.co.uk/CGI/INS...nuts&image.x=10&image.y=12&Ntk=Keyword+Search An on lone search for tee slot nuts uk should turn up lots of options.
 
There are tables online that outline what T-nut for slide and what the thread and dimensions are. The T-nut from the set - one of the $70 - $90 jobs off the internet in a red or blue tray have 7/17" T-nuts that fit, but I believe are bit too small and don't present enough surface area to the T-slot. I really don't want to blow the slot out.

I don't understand, the nut from the set and the nuts I purchased - both marked as 7/16" w/ 3/8" bolt hole do not match any chart by several thousands.

Unless others disagree, I lean with the suggestion by jmkasunich. The table's T-slots should have no paint and it seems to me the casting should have been machined - remove the paint and the high spots.

J

​

 
Damn Yankee said:
There are tables online that outline what T-nut for slide and what the thread and dimensions are. The T-nut from the set - one of the $70 - $90 jobs off the internet in a red or blue tray have 7/17" T-nuts that fit, but I believe are bit too small and don't present enough surface area to the T-slot. I really don't want to blow the slot out.

I don't understand, the nut from the set and the nuts I purchased - both marked as 7/16" w/ 3/8" bolt hole do not match any chart by several thousands.

Unless others disagree, I lean with the suggestion by jmkasunich. The table's T-slots should have no paint and it seems to me the casting should have been machined - remove the paint and the high spots.

J

​

Click to expand...
Table slots should be clean and paint free. Even in a new table they may not have identical dimensions, mine aren't. That doesn't mean they have to be re machined. It's far easier just to customize your tee nuts. They just need some minor touch up. Clean up the slots with some paint thinner and a scraper.

Making 6 or 8 tee nuts from some raw stock only takes a half day at most. I'm a beginner and that's what it took me. I made some nuts for my rotary table and it was fairly easy. It's a great first project. Remember not to tap the thread all the way through the tee-nut the last thread. Keeps one from accidentally breaking your table. You don't want the screw to touch the base of the table slots.
 
WobblyHand said:
Table slots should be clean and paint free. Even in a new table they may not have identical dimensions, mine aren't. That doesn't mean they have to be re machined. It's far easier just to customize your tee nuts. They just need some minor touch up. Clean up the slots with some paint thinner and a scraper.

Making 6 or 8 tee nuts from some raw stock only takes a half day at most. I'm a beginner and that's what it took me. I made some nuts for my rotary table and it was fairly easy. It's a great first project. Remember not to tap the thread all the way through the tee-nut the last thread. Keeps one from accidentally breaking your table. You don't want the screw to touch the base of the table slots.
Click to expand...
What brought this all about was my RT. I have no T-nuts, which led to one thing, then the next...
 
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