How a TC Bolt Works

[@tejonBiker]

Nice animation, thanks for sharing

[@dkeith45]

What an interesting idea! Seems to me there'd also be applications where you wouldn't want the spline snapped off though, to ease disassembly later.

[@basketcas3717]

I’m an ironworker and we snap bolts all the time. Sometimes there are beams or columns that don’t have to be snapped but more times than not if they ever plan to take them out it won’t be for a long long time if ever. Plus if someone down the line needs to take them off they have a piece to connect to this gun that will “break” the bolt loose. And if not that it can still be done manually no problem.

[@tcbolts]

Thanks for your comment - TCBs are simple and straightforward to remove even once fully installed. We do a shear wrench attachment specially suited for bolt removal. Please see our video on this here: kzbin.info/www/bejne/mIfZnICsd5l3qpo

[@dkeith45]

@@tcbolts I guess I'm thinking something like this might be cool for 'carriage bolts' going though wood. There are times I would prefer to use them, but unless the wood is tough enough to hold the square part, it's very difficult to tighten them. BTW, carriage bolts are often used to join beams, and for security to hold lock plates, door bolts etc where you want to prevent the bolt being removed from the outside.

[@zpridgen75]

That damn slug NEVER comes out without banging on it with a spud.

[@tcbolts]

In that instance we would recommend sending your shear wrench in for a service. The inner socket and/or ejector spring may be worn and need replacing.

[@alfredoreyes3543]

Also if that happens its probably because bolts were store outside expanding the metal or having dirt on them like rust or you gun its old and needs maintenance

[@basketcas3717]

These guys don’t understand in the field it don’t always work like that. Haha I’m an ironworker and we do what we need to keep going. Even if it means slamming your spud on it to get it to work haha

[@bobbysauer7826]

@@basketcas3717 hes still right?... yeah you gotta do what u gotta to get the job done, but the tool does need servicing?

[@FunnierK]

I can confirm, but it's because the inner socket have deformation after a lot of use, you know, it's a lot of torque over a little piece

[@caydenthompson126]

Thanks for the vid! Was wondering how this works. I'm a student.

[@kimobrense4038]

please enlighten me, why need to remove the end part?

[@tcbolts]

Hi Kim. TCB bolting assembly installation is complete when the spline shears off at the break-neck section of the bolt. In accordance with EN 1090-2, inspection after tightening requires that 100% of HRC bolting assemblies are visually inspected. Fully tightened assemblies are identified as those with the spline end sheared off, and a bolting assembly for which the spline end remains attached is considered to be under-tightened.

[@HossRashidi2536]

@@tcbolts Thanks for the video, but it still does not explain how the head does not rotate in the second stage.

[@tcbolts]

Hi Hossein. The co-efficient of friction between the underside of the bolt head and the steelwork is higher than the co-efficient of friction between the washer and the bearing face of the nut. Therefore during tightening the outer socket rotates the nut clockwise and the inner socket holds the spline without rotating. In the second (and final) tightening stage the torque required to shear the spline at the break-neck section is less than the torque required to rotate either the nut or the bolt head.

[@javierdiaz4955]

@@tcbolts Hi I have a doubt if instead of bolt with head we have a stud anti-clockwise, will the anti-clockwise nut spin while we are giving torque to the clockwise nut?

[@Mista808]

Meanwhile I'm on the toilet and unable to poop! 😬

[@MaxCaissie]

Same

[@hendroprabowo5555]

How we can loosen the existing bolt???

[@hendroprabowo5555]

Currently we do maintenance of TC bolt on existing structure. And we found some tc bolt already not tight anymore. And we to change the existing tc bolt

[@tcbolts]

TC bolts can easily be undone using a torque wrench. If there is not enough space you can also use a nut runner with a reaction bar socket.

[@alfredoreyes3543]

If the bolt got installed by force damaging the treads then using the shear wrench or cutting the nipples then all you can do its just to cut the bolt because using a wrench will just make the bolt spin

[@FunnierK]

Had a similar situation but I chose violence and a torch lol

[@PeterAthea]

​@@tcbolts vvvvvcfvvvv

[@daniellang494]

markings need to face out (was not done for washer)

[@tcbolts]

Hello Daniel, the markings for the NUT need to face outwards, however this isn't the case for the washer. The markings are on the flat face of the washer and regardless they wouldn't be visible once the nut is installed. The key visual inspection for the washer is the chamfer which needs to be oriented towards the nut as per the European standard and as shown in the video.

[@swamym040]

hi, Can anyone tell me. Is there any a325n and a325x bolts in tc bolts.

[@tcbolts]

All TCBs from Tension Control Bolts Ltd. are metric (not imperial.) Grade 10.9, CE marked and produced to European Standard EN 14399 series and are supplied with an eco-friendly Thermo Chemical Surface Modification called Greenkote® which offers, which offers superior corrosion protection as well as significant installation advantages. AMERICAN STANDARDS The standard specification for ASTM A490 metric bolts is detailed within the American standard F3125M. In 2016, ASTM officially withdrew specification A325 and replaced it with ASTM F3125 Our Greenkote class 10.9/10 metric TCB bolting assemblies in accordance with EN 14399-10 meet and/or exceed the mechanical properties detailed in F3125M. In terms of thread and shank, 'x' and requirements to have the threaded section or shank in the shear plane, this is viewed differently in the US & Europe, so we can provide guidance and transparency for specific questions but different standards are applicable depending on location. Also, please note TCB Ltd supply TCBs in 10.9 rather than 8.8 grade of steel so some requirements for x are not relevant to the higher grade of steel. Please email [e-mail] for further guidance and we can support.

[@swamym040]

@@tcbolts thanks for responding. But still my question is not satisfied with your reply. Are TC bolts having A325N &A325 X bolts. Or else To bolts doesn't have threads in shear plane right.

[@tcbolts]

@@swamym040 To detrmine the shank and the threaded section see the Grip Tolerance Chart on TCB website www.tcbolts.com/images/downloads/technical/GK_TCB_Grip_Tolerance_Chart_July_22_-_Standard.pdf TCBs do indeed have threads in the shear plane, 4 threads are mandated by the European standard. The European standard is different to the US standard and so the short answer is no, the European Standard does not have A325 & A325X. The longer answer is that the European Standard has a different stance and so the question does not arise when specifying TCBs, as the grade of steel is higher and the shear plane in the shank isnt in accordance with the standard. I appreciate its a convoluted and nuanced answer. Are you in the US?

[@swamym040]

@@tcbolts thank you so much for spending some time for me. I am working from India for us projects thru sds/2 software. I understand that there is no a325n & a325x for European stds. Generally for hex bolts A325N & A325X are there, In same way for TcBolts also having it not?

[@kerplop2263]

satisfying

[@Fundijones]

What this demonstration doesn’t tell you is that 1 out of 4 bolts are going to spin and that the nipple won’t break

[@alfredoreyes3543]

If that happens its because they force the bolt into the connection damaging the treads of the bolts

[@FunnierK]

@@alfredoreyes3543 if the thread fails when using the gun either is cross threaded or the bolt itself its defective

[@CookieTube]

It shouldn't spin. If so, your tool is broken. Both inner and outer sockets counter rotate against each other. This is not like a normal wrench.