External Hex vs External Torx

[_brian_]

I know this is a topic that has bounced around on every forum numerous times. I wanted to look at specifically external hex (the standard 6 point fastener) and external torx. The internal hex and torx fasteners have the same problem, the inside gets crud and rust and is harder to clean than the external, and once rounded, they are harder to remove than external type fasteners. While you can use them in a hole with a plug to protect them, that application is different than the standard bolt application.

In my short and limited real life experience with external torx fasteners, I believe they are the better fastener. For this discussion, I would also like to separate the ~8mm above and below, the 8mm could go either way. The reason for this is the smaller fasteners are easier to rust off the points, making the hex fastener better. However, fasteners of that small external torx sizes are often used in places where this is not much of an issue, at least in my experience and understanding. Those figures are just my guess / estimation / opinion, other thoughts welcome.

So looking at example, like the use of E20 for brake calipers, why would the E20 NOT be the better option over the hex head that would go on the same bolt size? Meaning, why might the hex fastener be preferred? This is aside from the reason that one does not have the tool.

I know that a common answer here is that the advantages of the external torx are hypothetical, and in real applications, it is not the case. If you share that opinion, could you justify it with some examples? I Am trying to understand and learn from the experiences of others, I have no intent on arguing the topic or even having a “winner”. I want this thread to be different by using actual examples of the applications.

 

[Tools4Me]

I prefer hex fasteners due to the cost of fasteners, fastener availability, and socket and wrench availability. There are also way more wrench types and socket styles available for hex heads.

In addition to wrenches and sockets, hex heads allow for turning with open end wrenches, pliers wrenches, adjustable wrenches, etc. You can't use any of those tools on an e-Torx bolt head without damaging it.

Many external Torx socket brands also do a poor job of getting the socket's chamfer angle to match perfectly (at least for some sizes) with the head of a standard e-Torx bolt head. As a result, there's lost socket engagement which increases the risk of stripping out the bolt head or damaging the socket. That dynamic often isn't obvious or easily visible.

These days, there are e-Torx Plus variants as well, and even shallow headed e-Torx and e-Torx Plus fasteners popping up, which require their own special minimally chamfered sockets to turn, so the fastener landscape is becoming more messy overall for little to no functional benefit. I could be wrong, but the e-Torx bolts I have wrenched on have also all been metric, so if you need your bolts to have SAE threads e-Torx might not even be an option.

I also prefer hex heads for tight area box wrench work, because an e-torx box wrench is a 6pt design and that's all it can be. The handle has to be able to turn a full 60 degrees before the box end can be removed and re-applied to continue loosening or tightening a bolt. Often not easy to achieve. With hex headed bolts, 12pt box wrenches are common and they only require 30 degrees of rotation before the wrench can be re-positioned to allow loosening or tightening to continue. Yes, there are fine toothed ratcheting box wrenches in both styles, but ratcheting box wrenches don't fit everywhere a standard box wrench does.

 

[_brian_]

Wow, that is a lot. I get your point on the tools aspect, where you need a certain tool for only that fastener. I also agree that the fasteners come at a higher cost, and so do the tools for the most part. They do have e-torx fasteners with SAE threads, but they are not so common as you pointed out with the fastener type in general. I have not run into a place where the angle made a difference either way, but in concept, you have a point there. I do not have ratcheting e-torx wrenches, but I have sockets (low profile and regular) and double box end wrenches.

I have heard a few times now that some tools are poorly made, incorrectly made, or what the actual case might be. Is this specific to certain brands, or is it sort of hit and miss with brands? I have not experienced this issue, so I am curious to know more on the issue.

My e-torx experience has been with cruise control radar sensors, brakes and chassis/suspension mostly. For those applications, I seem to find them better. It seems from your experience, you have more under the hood type applications, where the number of points and angles cause issue? My most recent, being on brakes, I like the fastener type as the grip of the socket is better in feel. I have done more brake jobs than I can count, so I have a good deal of hex fastener experience on brakes. To me it provided a more solid grip I guess is a way I can say.

To add on my experience, I really prefer torx fasteners for screws. Although the point made here on cost and availability is 100% true. As most all others, I dislike the slotted fastener. Phillips is ok, but we all know the weakness there. I use Vessel JAWS cross point drivers for those now for better results. I have a set of Robertson / square drivers, Tekton tri lobe, and have great luck with that fastener in general, they are my go-to for drywall. I prefer the torx fastener for general wood work, whether a deck, a bench, table, stool, etc, I find the fasteners just go easier with less error. Error being cam out, slipping off the fastener from user instability, etc. I also like torx in electronics. When opening up computers for example, I find the fasteners far superior when it comes to not stripping out. When the phillips fasteners are used, it seems that the drivers often do not fit right, and a few different sets of micro drivers are needed for the best hopes of finding a brand that fits right.

 

[F-22]

For sure, the etorx offers many advantages in strength. As such, etorx can be used in most high tensile bolt applications.

While the hex head isn't bad by any means, the etorx shape certainly induces fewer notching effects. That said, the flanged hex head screws are also an improvement (often common in the JIS standard), and the next step are probably 12-point heads. But they still have sharper edges and more sudden geometry changes than etorx.

Another advantage of etorx - with the fat flange, usually the socket does not take up a lot more space than the head, while on a hex head with no flange the socket is always larger.

 

[2ndGearRubber]

Etorx is dumb and offers little advantage in many vehicle applications. An m6 bolt torqued at 71in/lb does NOT need etorx for maximum torque application. You want to stick that stuff in connecting rods or head bolts fine. But just sticking it everywhere with no actual benefit is silly.

 

[ecotec]

I have yet to run into ETorx+ yet… where have you guys been seeing those fasteners?

I get the premise that they would be better in a high torque situation.

 

[cmandp]

I think E-torx is worse on areas of the vehicle that are prone to rust. Areas like suspension, hubs, brakes, chassis,etc. I've seen some E-torx that are almost unidentifiable. These were sway bar link ball studs, E6 or E7 size maybe? They have too much detail that needs to remain in order to be able to take torque. Granted similar size external hex did no better in a similar application and internal hex was laughable.

I like e-torx if they are in a clean area but then what advantage does their high-torque capability have over traditional external hex if it's not a high strength fastener?

 

[tamaraw]

I also prefer hex heads for tight area box wrench work, because an e-torx box wrench is a 6pt design and that's all it can be. The handle has to be able to turn a full 60 degrees before the box end can be removed and re-applied to continue loosening or tightening a bolt. Often not easy to achieve.

On a flat box end wrench, if the head pattern is rotated 15 degrees off "straight", then the wrench can be flipped over to get extra angle and let you turn a six point fastener with only a 30 degree working angle. Facom, Hazet, Stahlville, etc. make their e-torx wrenches like this and Nepros have 6 point hex wrenches with a similar pattern.

 

[_brian_]

I have yet to run into ETorx+ yet… where have you guys been seeing those fasteners?

I get the premise that they would be better in a high torque situation.

From what I understand, they are used on Ford truck beds and Corvette on some panels under dash hood I believe. Those are new models I refer to. I have never seen one though.

 

[ecotec]

From what I understand, they are used on Ford truck beds and Corvette on some panels under dash I believe. Those are new models I refer to. I have never seen one though.

Thank you.

 

[_brian_]

Etorx is dumb and offers little advantage in many vehicle applications. An m6 bolt torqued at 71in/lb does NOT need etorx for maximum torque application. You want to stick that stuff in connecting rods or head bolts fine. But just sticking it everywhere with no actual benefit is silly.

Do you have any examples to share? I am looking for some context behind opinions so they make more sense. I can understand your statement on the fasteners having their place, I believe I stated a similar opinion as well. Using the use on brakes I mentioned, I did not consider torque applied, but the fit of the socket to the fastener. It seemed to provide a more solid fit, I am not sure the proper words to explain. It felt more secure to the fastener, more solid.... if that makes any sense. I understand my experience is limited with the fasteners, so I am hoping to learn more from the experiences of others.

I also wonder from your statement if there is a convenience factor in sticking with the same style fastener throughout. Is it preferable for a person to grab a set of etorx for the entire job, or to grab a set of hex and etorx? To me, a non professional, I would say it does not matter. I get more annoyed when there is a mix of SAE and metric hex fasteners. So, if the etorx fastener is used in some places, is there a reason NOT to use them in all places? Is there an advantage to using a second type of fastener?

 

[richfinn]

Started seeing a lot of external torx when angle torque specs were introduced in Europe.

My best guess is that they already had the tools for torque critical stuff and started using them wherever it was convenient.

Probably a combination of cost/quality control at the factories.

 

[2ndGearRubber]

I have yet to run into ETorx+ yet… where have you guys been seeing those fasteners?

I get the premise that they would be better in a high torque situation.

Honda engine mount nuts on the r18 4cyl engines are etorx plus, low profile too I believe.

Nissan uses them for flywheel bolts, again, low profile. Cause I'm sure a 12 point 14mm totally couldn't have secured that.

 

[VolvoRyan]

E-torx may simply be easier to load an assembly machine/device with at the factory. Concern for the end user isn't really a high priority. The reasoning could just be that some egghead way up the supply chain did something "just because".

At the dealership level, techs just tend to memorize what size/type a fastener is, so they can grab the right tool.

I'm pleased that Volvo hasn't really graduated to anything beyond the two kinds of "hex" and torx.

-Ryan

 

[2ndGearRubber]

Do you have any examples to share? I am looking for some context behind opinions so they make more sense. I can understand your statement on the fasteners having their place, I believe I stated a similar opinion as well. Using the use on brakes I mentioned, I did not consider torque applied, but the fit of the socket to the fastener. It seemed to provide a more solid fit, I am not sure the proper words to explain. It felt more secure to the fastener, more solid.... if that makes any sense. I understand my experience is limited with the fasteners, so I am hoping to learn more from the experiences of others.

I also wonder from your statement if there is a convenience factor in sticking with the same style fastener throughout. Is it preferable for a person to grab a set of etorx for the entire job, or to grab a set of hex and etorx? To me, a non professional, I would say it does not matter. I get more annoyed when there is a mix of SAE and metric hex fasteners. So, if the etorx fastener is used in some places, is there a reason NOT to use them in all places? Is there an advantage to using a second type of fastener?

Gm 1.4 is a good example. Valve cover, thermostat housing, water pump, water outlet, all etorx. However the torque specs based in bolt diameter and pitch are no different than if there was a 10mm head on those m6 fasteners like we did for 30 years. The entire areas I mentioned could have been secured with 13mm (m8) and 10mm (m6) hardware. And the torque specs reflect that.

So there is no need for etorx for strength. And now I need to buy etorx low profile, swivels, deep, shallow the whole 9 yards to do what the 10mm sockets I already had would have done fine. They don't make 1/4 drive impact universals in etorx. So now I have to use a larger combo of socket and adapter. Or lose my favorite combo for engine bay work.

Etorx simply isn't needed in the application. It's just an engineering flex. Same deal as etorx suspension bolts. They get siezed in the bushing sleeve, and I can shred out the bushing with a 6 point socket. So etorx is now harder to use and slip tooling onto, is 6 point so I need spline wrenches as otherwise no etorx wrench is going to fit, limiting access, and offers no additional advantage.


It's cool and all, use it for head bolts. It makes zero sense and is stupid to use triple square for undertray bolts, or etorx to hold on a valve cover. For what? What was gained? Durr better get out the 5 point security torx for that mass air flow sensor. God forbid somebody steals it or molests it if we just used regular torx.

 

[2ndGearRubber]

In defense of etorx, it's better than 12point which just rots into a circle in the rust belt.

Like the idiots at jeep that held the wheel bearings in with 13mm 12 point. Aftermarket replacements are 15 or 16mm 6 point. Which there is plenty of room for. And can reach the torque spec.

 

[boom_bap]

Etorx has a smaller head profile for the same shank diameter. There is a valid reason for them to exist. A hex head would shear before an etorx. Torx fasteners on the other hand can go die in a grease fire. Hex head is preferred for most applications but but etorx can be used in tight places for sheer strength of the bolt matters IE in a bore, studs with a hex nut on top etc.

 

[AdAstra]

As alluded to earlier, manufacturers are using these primarily to lower their assembled cost, and in some cases it helps to make things smaller because of lower socket clearance needed for a given fastener size/torque.

The auto industry is a very low margin business, so controlling cost is hugely important.

Maintenance and repair difficulty are very low on their list of concerns, especially if it's not expected to need service until after the warranty period.

This brochure details the advantages for assembly lines.

 

[_brian_]

So if I am understanding all correctly, no ne seems to see an advantage outside of the manufacturing process, generally speaking?

 

[dchawk81]

I'm wondering how they hold up to impacting. More contact points but smaller and maybe more fragile?

I'm talking real impacting, by the way, not the inch pounds stuff a driver can do.

 

[_brian_]

I'm wondering how they hold up to impacting. More contact points but smaller and maybe more fragile?

I'm talking real impacting, by the way, not the inch pounds stuff a driver can do.

I would be interested in that answer as well. I do not have any impact external torx sockets. I only have impact triple squares and normal torx. The larger sizes for torx, like the T80 3 inch, take an impact quite well.

 

[2ndGearRubber]

I'm wondering how they hold up to impacting. More contact points but smaller and maybe more fragile?

I'm talking real impacting, by the way, not the inch pounds stuff a driver can do.

The lead-in taper on them makes bouncing an issue if you don't have a firm grip or are using a long extension. I can swat a 10mm universal on a long neck ratchet into the abyss and remove a thermostat housing bolt. Already spinning the ratchet at full speed, stuff it down approximately where the bolt is and it will pull it. Etorx wants to grab and the reject the socket. You need 100% engagement. Etorx really doesn't like side loading. So imagine you have some m16 caliper bolt, 150ft/lb of torque, locktite from the factory. You really need to be pulling prependicular from the fastener. Flex head ratchet, extensions, bolts breaking free then grabbing again, jerking motions- all make etorx want to pop the socket off.

Triple square is pretty impact friendly. Much more than torx and WAY more than internal hex/Allen. Which may just be the worst design outside a screwdriver.

 

[cmandp]

I should mention my experience is from working on my own, family or friends vehicles. I'm not a mechanic like 2ndGear.

But this.

Much more than torx and WAY more than internal hex/Allen. Which may just be the worst design outside a screwdriver.

Internal hex has no business being on a vehicle where it is exposed to air lol. Love it for SHCS in the machine shop or on fixtures. On a vehicle no way. Even the the GM cailper bolts on S10s/El Caminos/Chevelles/etc that use a 3/8" allen wrench get crusty and wear out. I just replace them every few brake jobs.

Small 4mm hex to hold a ball stud from spinning? Forget it. It bearly works for install when new.

 

[_brian_]

Triple square is pretty impact friendly. Much more than torx and WAY more than internal hex/Allen.

Thanks for expanding on the topic, making it more complete.

I generally try to avoid impact on bit socket type applications. I never really have comfort with it. I do use impact though on T80 lug bolts, never had any issues. I assume the same would hold true to most of the larger bit sockets.

 

[2ndGearRubber]

Thanks for expanding on the topic, making it more complete.

I generally try to avoid impact on bit socket type applications. I never really have comfort with it. I do use impact though on T80 lug bolts, never had any issues. I assume the same would hold true to most of the larger bit sockets.

Usually the bigger things get, the less of an issue it is.


For instance, stick a t15 in a t25, aint happening. Neither is a 10mm on an 8mm head. But a 36mm socket will remove a 34mm axle nut. As the fastener gets bigger, 2mm or whatever becomes a lower percentage of the total size of the mating surface, and is therefore less of an issue. On a 1000mm nut the difference in oversize of the socket to allow it to slip onto the nut may be 2mm.

 

[F-22]

Another point - if I see an etorx fastener, I always assume the torque on it is important and I'd use a torque wrench on it. Not so with generic hex head fasteners.


Not really more to it, but you are more likely to use the fancy tools for the fancy fasteners.

 

[Wakefield]

I think E-torx is worse on areas of the vehicle that are prone to rust. Areas like suspension, hubs, brakes, chassis,etc. I've seen some E-torx that are almost unidentifiable. These were sway bar link ball studs, E6 or E7 size maybe? They have too much detail that needs to remain in order to be able to take torque. Granted similar size external hex did no better in a similar application and internal hex was laughable.

I like e-torx if they are in a clean area but then what advantage does their high-torque capability have over traditional external hex if it's not a high strength fastener?

(External) Spline? Also has more torque capacity than hex? But does it have the same disadvantage in a rusty environment?

 

[Leaflessshadetree]

Each style has it's place. Sometimes a certain style is better in a certain applications/location.
More than once I've been in a situation where an open end wrench would work but a box end or socket would not. If the bolt/nut was anything but hex (or square) I don't know what I would have done. I've also been in situations where the fastener being E-torx worked out a lot better than hex.
Last week I replaced the pins in a brake caliper. The old were torx the new were hex. A rusty (or even rounded off) hex would have been much easier to deal with.

 

[Bigblue&Goldie]

Just discovered Ford is using Torx+ on the newer trucks.....off to buy a set.

 

[_brian_]

I've been in a situation where an open end wrench would work but a box end or socket would not

This is a point I dd not consider / think of. While it is a situation I personally find rare, it is for sure something to consider.

Just discovered Ford is using Torx+ on the newer trucks

In addition to the external torx plus? I have a set of torx plus, both standard and tamper proof, but I do not have any external torx plus... yet.

 

[VolvoRyan]

Sometimes I wonder if manufacturers use different fastener types to differentiate between things you should and should not unscrew for routine maintenance. For example, remove this fastener on a trans, and now the band is free and you day is ruined.

All I know is that I'm glad my wife's run of Fiats ended when we got rear-ended by a semi-truck (fun!) right before the pandemic. We replaced with a second-hand, first-gen XC60. Not only did I dodge the E-Torx bullet.... but somehow Volvo parts are cheaper than Chrysler.

-Ryan

 

[dchawk81]

The lead-in taper on them makes bouncing an issue if you don't have a firm grip or are using a long extension. I can swat a 10mm universal on a long neck ratchet into the abyss and remove a thermostat housing bolt. Already spinning the ratchet at full speed, stuff it down approximately where the bolt is and it will pull it. Etorx wants to grab and the reject the socket. You need 100% engagement. Etorx really doesn't like side loading. So imagine you have some m16 caliper bolt, 150ft/lb of torque, locktite from the factory. You really need to be pulling prependicular from the fastener. Flex head ratchet, extensions, bolts breaking free then grabbing again, jerking motions- all make etorx want to pop the socket off.

Triple square is pretty impact friendly. Much more than torx and WAY more than internal hex/Allen. Which may just be the worst design outside a screwdriver.

I have an etorx set but have yet to use them. Looking at them I can tell they need to be fully on before you turn but I wasn't even considering that since I don't prespin a hex either. Lol.

 

[bwringer]

Stepping back a bit...

If an application truly needs a stronger fastener, higher torque, and more engagement, then the simplest solution is a 12 point fastener head. These are quite common in aviation, and they're found from time to time in cars and motorcycles in things like cylinder head or piston rod fasteners. My Toyota uses 12 point CV axle nuts that take a 30mm socket. Pretty much everyone already has the tools needed, or can easily grab a set of 12 point sockets, and 12 point tools can of course still be used on the more common 6 point fasteners.

Anything else, like inventing idiotic new types of drive systems, is nothing but pure engineering wankery, or perhaps a misguided attempt to restrict access, or enhance future service revenue via requiring special tools.

I'm not really buying the "easier automated assembly" line of BS either...

I think true engineers would want to keep things simple as possible, and stick with what's already in widespread use. But apparently there's a certain stripe of engineer that really gets off on the idea of inventing some useless new "standard" that no one wanted or asked for, or perhaps trying to make money from licensing "Torx", Torx Plus", etc.

I will admit, grudgingly, that internal Torx fasteners CAN work fairly well on the RARE occasions they're employed correctly on SMALL fasteners. Internal hex is always simpler and better when you need a socket head, but Torx can do the job. However, **** like an undersized, shallow, T50 button head on a 10mm thread suspension bolt is blatant, insane malpractice.

There's also a whole sub-genre of this brand of masturbatory ******** based on keeping people out of their devices; security torx, tri-wing, one-way or one-time fasteners, pentalobe, etc.

It's a stupid, expensive, useless arms race, there's never a good reason for inventing weird new fasteners, and I for one am tired of it.

 

[_brian_]

Regardless of other thoughts, I need to agree on the licensing issue. If anything it leads to confusion as we now have the terms torx and star used interchangeably for no reason. The tamper proof stuff... I think it has its place. Public restrooms for example, sure. I get it. A car I purchased, no. Especially when I can just buy the tools and remove the fastener anyway. All it does is require me to have more tools and spend more money, it is not keeping me out of anything.

 

[dchawk81]

The fastener that really gets my goat is this one:

 

[whateg01]

I have yet to run into ETorx+ yet… where have you guys been seeing those fasteners?

I have seen them recently on the intake of a 99 ranger, in a smaller size. I also had them holding the front subframe on a 95 t bird in a larger size.

Edit: those aren't +. My bad.

 

[_brian_]

The fastener that really gets my goat is this one:

That is just awful. I have the bits for those fasteners, but I am happy to say I have never used them. Aside from security, I am not sure what purpose that even serves. Grip of tool on fastener cannot be good at all.

 

[dchawk81]

That is just awful. I have the bits for those fasteners, but I am happy to say I have never used them. Aside from security, I am not sure what purpose that even serves. Grip of tool on fastener cannot be good at all.

My rear lights were installed with those too. The kid at the shop I bought it from tried to remove a rusted one and broke 3 bits before I said do you have a grinder? He said yeah why? I said I'll remove it.

He wasn't allowed to do more harm than was already there so he didn't want to damage the stainless steel bezel, inevitable with a grinder. Since it was my truck I could.

So I ground the heads off and let him take some vise grips and remove the remaining studs. Then I told him to use hex self tappers to install the new light.

 

[Dig Doug]

This Thread Needs More PICS…..

INSIDE/ OUTSIDE - reverse Whatchamacallits, gets a little confusing….

For building / Framing I like nail guns (corded or cordless) and T 25 screws and don’t forget BIG ol bolts / nuts for buckets and beams !

 

[Dig Doug]

The fastener that really gets my goat is this one:

sombody was stealing Storm Drain grates from parking lots and drive ways on sone if our industrial developments a few years back! We used those bolts drill and tapped used anti seize and a dab of silver caulking to cover the bolt head!