I think I read on here or another forum about tee nuts cracking, anyone know which brand?
By chance I looked at mine today and 3 are cracked and are only a couple of months old.

What!? How!? What material are yours made of? I've been using the same two sets for probably 300 sessions without a crack. That's crazy.

The brass ones can crack. I use brass because if I run aground I want the nut to fail not the box.Haven't seen any SS ones crack

Not sure of material but doesn't look like brass

Hard to tell from the pics but if it's a gold colored material (probably brass), all of mine have cracked in the same way as well. Never cracked a stainless one yet though. I keep the the new gold ones I have around for emergency use and then would only use them in the front position.

I doubt they would break though. They crack only up to the thicker area. We used to use a threaded nylon plate for windsurf fins so the fin tab didn't break off, but then surf style fins would chop into the board behind the box when the plate broke.

I think tracks are 9.1mm, so a 9mm top fits and with M8 screws the wall is only 0.5mm thick. If the top of nut is even narrower then wall even thinner. I'm going to have a good look at my nuts;-)

i read somewhere ages ago that this can be caused by the bolt not going through the nut sufficiently...to make sure it pretrudes the other side

i checked my brass ones and 2 out of 4 had small hairline cracks
I now have S/S nuts - but also changed my bolts to be 5mm longer - i think i swapped the std f-one 25mm for 30mm bolts

But obv you need to ensure they are not too long and bottom out on the botton of the track!

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robbo1111 said..
The brass ones can crack. I use brass because if I run aground I want the nut to fail not the box.Haven't seen any SS ones crack

Have not seen a nut save a box yet sorry.

Plenty of fkd up tracks I fix and the rest of the assembly is fine....

Stainless is better for sure but some will not quiiiite run thru some tracks (track cools after moulding and closes just a smidge) so always check before getting to the beach!

I blame the board builders who took the lazy way and used SURFBOARD boxes for tracks and stuck windsurfer mast track nuts in them. They did not fit, so the windsurfer track nuts got trimmed a tiny bit narrower to fit the crap surfboard boxes.

Windsurfer tracks are WIDER by a small amount and original brass T-Nuts are THICKER. So they never, ever, failed in 40 years of use on windsurfers. Jumping 30 feet and held in by ONE t nut.

Ever try windsurf fin in a surfboard. It does not fit. Too thick. Too deep. Yeah, windsurf boxes were built stronger for a reason 40 years ago. They stopped using crap surfboard boxes because they failed.

Put calipers on your brass T-nuts and toss the ones made dangerously thin. I've found the Axis nuts to be consistently thick enough. Many other brass ones I measured, had a few too many under sized mixed it.

Oh, while I'm ranting.haha. Ever have your over tightened T-nut stop sliding in the tracks because you dented the plastic. Yeah, that's your board builder using crap surfboard tracks, lacking the high glass fill content in the plastic molding process, like windsurf tracks use, without ever denting the plastic. Use Chinook tracks to be sure it's a real windsurf track.

^^ bloody spot on

No excuse for the nuts ripping through tracks that we have seen - in some cases for a few years - by some brands.

No excuse for thin walled t-nuts.

Unfortunately with a new sport every man and his dog jumps in making stuff..... the same happened with kiteboard fails for a while (30yrs ago) and SUP fails (20yrs ago) and sorry foilers if you want quality you get a board made by an old windsurf guy... its gonna be better than your eggshells board.

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Mark _australia said..
^^ bloody spot on

No excuse for the nuts ripping through tracks that we have seen - in some cases for a few years - by some brands.

No excuse for thin walled t-nuts.

Unfortunately with a new sport every man and his dog jumps in making stuff..... the same happened with kiteboard fails for a while (30yrs ago) and SUP fails (20yrs ago) and sorry foilers if you want quality you get a board made by an old windsurf guy... its gonna be better than your eggshells board.

Mark and/or DWF, any boards in particular you would call out in both the "old windsurf guy," and the "eggshell" categories?

I have just had a closer look at 8 tee nuts, 4 from 2 different brands.
1 set as per my photos above are about 1 month old the other set 12 months plus.
The older set is showing signs of cracking.
All seem to be stainless steel and some are very poorly machined ie the flat section is not level.
I assume all brands just buy tee nuts in and don't make their own.
M8 bolts leave almost no room at the sides and the thread cuts into what is there so seems cracking is inevitable.

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robbo1111 said..
The brass ones can crack. I use brass because if I run aground I want the nut to fail not the box.Haven't seen any SS ones crack

Brass is used because it is one of the metals less prone to galling.
This is quite important as not many people are conscious of the risk of galling, as they discover when using titanium screws, which extremely prone to galling and must be screwed with care.

PS: I guess if you run aground and the nuts break, the damage will be substantial, as only some of the nuts will break, the foil will rotate around the remaining ones and the leverage will destroy the boxes anyways.

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warwickl said..
I have just had a closer look at 8 tee nuts, 4 from 2 different brands.
1 set as per my photos above are about 1 month old the other set 12 months plus.
The older set is showing signs of cracking.
All seem to be stainless steel and some are very poorly machined ie the flat section is not level.
I assume all brands just buy tee nuts in and don't make their own.
M8 bolts leave almost no room at the sides and the thread cuts into what is there so seems cracking is inevitable.

Pretty sure the set in the photo are brass, the plating looks to be coming off in places, and you can see the "brown" oxidised brass under it.

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choosywinger said..

Mark _australia said..
^^ bloody spot on

No excuse for the nuts ripping through tracks that we have seen - in some cases for a few years - by some brands.

No excuse for thin walled t-nuts.

Unfortunately with a new sport every man and his dog jumps in making stuff..... the same happened with kiteboard fails for a while (30yrs ago) and SUP fails (20yrs ago) and sorry foilers if you want quality you get a board made by an old windsurf guy... its gonna be better than your eggshells board.

Mark and/or DWF, any boards in particular you would call out in both the "old windsurf guy," and the "eggshell" categories?

Yeah. Naish Hover and Konrad tracks are a joke
to be fair, Naish learned.

Eggshell varies but if it's not full sandwich and it's rubbed thru carbon it will be a candidate.
let's just say I now have a surcharge for repairs on a certain brand it's such a disgrace you can't sand next to a repair without creating another one.

As for old windsurf builders well I do know one really well

These Sabfoil adapters let you use M6 screws on M8 carbon mastplates.
M6 box inserts have more margin of metal around screw.

Sadly they come in 3's so you need two sets at 8 eur a set...
And they do to rust a little ,so not a brilliant deal from Sabfoil :(

The 8mm hole in the T nut does come very close to the edge, still should not really crack unless it's drilled off-centre. Here are some pics of new ones that you can see how close they are drilled, I have used these same bolts for over a year and no cracks.
You can also use them upside down which in some ways makes more sense anyway but you will need to run at least a 30mm bolt if you do this.

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paul.j said..
The 8mm hole in the T nut does come very close to the edge, still should not really crack unless it's drilled off-centre. Here are some pics of new ones that you can see how close they are drilled, I have used these same bolts for over a year and no cracks.
You can also use them upside down which in some ways makes more sense anyway but you will need to run at least a 30mm bolt if you do this.

Hi Paul
Do you sell 316 stainless steel tee nuts?
I bought some from you years ago however, sold them with a mast.

T-nuts are cracking when the screws are too short / not fully engaged into the lower portion of the T-nut before you pull them tight. Load comes when the screws are tightened and the screws are just in the upper portion of the T-nut with really no sidewall thickness. The upper portion of the T-Nut can't handle the load and cracks. (Which normal nuts do you know that work where someone cut the sides off like on T-nuts? It just can't work if they are not fully engaged in the part that has a thicker sidewall. See if you get some SS316 of Ti nuts and the right screw length that fully engages into the T-nuts before you pull them tight and this will be sorted.

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UliSommerlatt said..
T-nuts are cracking when the screws are too short / not fully engaged into the lower portion of the T-nut before you pull them tight.Load comes when the screws are tighten on and the screws are just in the upper portion of the T-nut with really no side wall thickness on the side. The upper portion of the T-Nut can't handle the load can cracks. See if you get some SS316 of Ti nuts and the right screw length that fully engages into the T-nuts before you pull them tight and this will be sorted.

Excellent point.
I'll check that however, the board and mast with supplied tee nuts and bolts are from the same brand.
Also when I install up a new a new set I double check bolt lengths.
Having said that I have been switching between boards a bit lately and not checked ??

What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

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camerongraham said..
What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

No advice in the instructions.
I am off the water atm so time to do some checking.

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warwickl said..

camerongraham said..
What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

No advice in the instructions.
I am off the water atm so time to do some checking.

Narrow bit up, otherwise, the threads of the screws will eat in the sidewalls of the track. The narrow bit of the N-nuts is there to guide the screws in the track to prevent this.

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UliSommerlatt said..

warwickl said..

camerongraham said..
What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

No advice in the instructions.
I am off the water atm so time to do some checking.

Narrow bit up, otherwise, the threads of the screws will eat in the sidewalls of the track. The narrow bit of the N-nuts is there to guide the screws in the track to prevent this.

Thanks more logic, are you a mechanical engineer?
I knew everything thing you have said but had not applied it to this situation.

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warwickl said..

paul.j said..
The 8mm hole in the T nut does come very close to the edge, still should not really crack unless it's drilled off-centre. Here are some pics of new ones that you can see how close they are drilled, I have used these same bolts for over a year and no cracks.
You can also use them upside down which in some ways makes more sense anyway but you will need to run at least a 30mm bolt if you do this.

Hi Paul
Do you sell 316 stainless steel tee nuts?
I bought some from you years ago however, sold them with a mast.

Yeah here is a link to them www.oneoceansportsaustralia.com/accessories/p/8mm-bolts-foil-board

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camerongraham said..
What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

I have used them both ways and had no issues either way, I didn't see it eat into my tracks so not sure if that would be an issue or not but maybe i will run them upside down for the next 1000 kms of DWing and do the test 100%

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UliSommerlatt said..

warwickl said..

camerongraham said..
What is the recommended orientation of T nuts in the tracks ?
Is it T or _|_ ?

No advice in the instructions.
I am off the water atm so time to do some checking.

Narrow bit up, otherwise, the threads of the screws will eat in the sidewalls of the track. The narrow bit of the N-nuts is there to guide the screws in the track to prevent this.

You would hope there was no movement at that point. AFS just use a plate and I have seen not evidence of thread eating into the tracks.

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warwickl said..

UliSommerlatt said..
T-nuts are cracking when the screws are too short / not fully engaged into the lower portion of the T-nut before you pull them tight.Load comes when the screws are tighten on and the screws are just in the upper portion of the T-nut with really no side wall thickness on the side. The upper portion of the T-Nut can't handle the load can cracks. See if you get some SS316 of Ti nuts and the right screw length that fully engages into the T-nuts before you pull them tight and this will be sorted.

Excellent point.
I'll check that however, the board and mast with supplied tee nuts and bolts are from the same brand.
Also when I install up a new a new set I double check bolt lengths.
Having said that I have been switching between boards a bit lately and not checked ??

Unfortunately, you can't assume same brand mast bolts and boards fit. I had two Fanatic boards, one had deeper boxes and I needed longer 35mm bolts to go fully into nuts, in the other board the supplied 30mm were fine.

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patronus said..

Unfortunately, you can't assume same brand mast bolts and boards fit. I had two Fanatic boards, one had deeper boxes and I needed longer 35mm bolts to go fully into nuts, in the other board the supplied 30mm were fine.

Yes!,this is very important and a mess for me.
I use different foil brands,board brands plus different shims for winging vs supfoiling.

Different foilboxes have different inner dimensions,same with mastplate thicknesses.

Always good to check that screws are not too long/short when messing around with new gear.
I put the mastplate on the track with shim if any (no insert under it) and put the screw in, it should have at least 1mm or more distance from bottom of box.
If you crank the mastplate down and the screw is too long you might crack the box.
I would risk saying that modern 100% carbon foilboxes will be more brittle and prone to cracking from this,plus the inside dims might be totally different from plastic boxes.

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mcrt said..
These Sabfoil adapters let you use M6 screws on M8 carbon mastplates.
M6 box inserts have more margin of metal around screw.

Sadly they come in 3's so you need two sets at 8 eur a set...
And they do to rust a little ,so not a brilliant deal from Sabfoil :(

An economical alternative would be nylon insulating washers /sleeves /bushes, which neatly adapt an m6 bolt to an m8 hole and also help protect an alloy mast-plate from galvanic corrosion.

M6 bloody bends. There is a reason we went away from it in windfoil years ago. Just use M8, properly. ie: with a decent t-nut and long enough bolt.

So much fluffing around and 'what if' in this thread. Its really easy. Again, use decent hardware properly.