Why 6pt and not 12pt?

[_brian_]

Twist on a common question.. Why are 6 point fasteners still the norm when we can use 12 point? If my math is correct, a 12 point fastener and socket offers somewhere around 30% more surface contact between the fastener and the socket and are able to allow for more torque to be used with the same size bolt head. So why even use a 6 point fastener? The change from 4 to 6 point was made, why not make the change from 6 to 12? My initial thought was because the 6 point is so common, but in reality, smaller tool sets often some with 12 point sockets and not 6.

 

[garfunkle24]

Cheaper to make 6 point.

 

[2ndGearRubber]

12 point also rots away worse.

 

[Benito]

30% more surface contact and more torque WHEN NEW maybe

 

[subroc]

Torque requirements are far more than fastener style. The fastener material, thread design, material being joined, application, etc. Far more goes into torque than the faster head design.

 

[Handyandy23]

12 point also rots away worse.

This, would hate to see a 12 point suspension bolt in the rust belt / north.

Most newer socket and wrench tech is designed around grabbing on the flats of a fastener because the corners are weaker and fail, especially when rusty. 12 points would decrease those flat areas and wouldn't leave much meat to grab onto.

 

[Tools4Me]

Until this post, GJers have only been guessing and/or hypothesizing. The real answer is that it's a conspiracy between Snap-on and the fastener manufacturers. If all fasteners became 12pt, Snap-on would no longer be able to charge an arm and a leg for Flank Drive Plus wenches. The bottom would also immediately drop out of the double open end wrench market.

 

[Boogerman]

Cheaper to make 6 point.

Along with rusting problem, this primary reason. Takes more precision to make 12 point, 6 point allows more slop. Same reason cheap manufacturers started making 6 point sockets, and then they became norm as people moved toward cheaper, lower quality tools. A 6 point socket can still work with greater tolerances, and a 12 point socket has to match bolt more closely, so tolerances in the socket need to be held closer. Same with the bolt head, so 12 point bolts much more expensive.

To look at the result, not the reason, we would say "because 6 point work better".

 

[richfinn]

It would be overkill making all fasteners 12 point, where it's required auto manufacturers do utilise 12 point (mostly torqùe critical internal engine components like con-rod bolts etc.)

Using them under the car exposed to road salt etc. Is a really bad idea as has been suggested.

I think using 12 point for critical fasteners maybe "encourages" techs to actually torque critical fasteners to spec, rather than just blasting them with an impact wrench (please don't judge me )

 

[dnschmidt]

^^^^^^ Right On! I love 12 point fasteners and I love ARP fasteners but when a set of head studs for a Ford 6.0 Turbo Diesel cost over $1000 you can afford to make them fit properly. I live in Phoenix now so the rust issue isn't applicable to me but when I was back home in Pittsburgh these would have been a disaster as all bolt heads over time would have been reduced to perfect circles.

 

[Big Bad Dad]

You ever try to use an adjustable wrench on a 12 point fastener?

 

[Wiz02]

I will second all the comments about rust and 12 point fasteners being a terrible idea. Since I don't do internal engine work (yet) all my 12 point sockets are in the maybe I will use this someday drawer.

 

[kbeefy]

My knipex wouldn't work on 12pt

 

[Oldsnapper]

You also can't use an open end wrench on a 12 point nut or bolt

 

[rsanter]

We do, there are select applications on cars that use the 12pt

Example would be ford drive flange at the rear end

 

[ex-x-fire]

I'd be much harder to make a rounded off rusty 9/16 head to 1/2 with a file.

 

[_brian_]

We do, there are select applications on cars that use the 12pt

Example would be ford drive flange at the rear end

Yes, they are used in some places. Ford, Mercedes, aftermarket performance parts, drive shafts (which are exposed to salt in the rust belt), etc.

I dont really view the not being able to use certain tools as a reason though. You cannot use a flat head on a cross point screw, you cannot use a torx bit in a hex fastener, you cannot use any open end wrench on an external e-torx, etc. Every fastener has a set of tools that can be used on it as well as tools that cannot. My opinion at least is that the tools should not dictate what fastener is used, if there is an advantage to using a specific fastener, that fastener should be used... assuming the fastener is pre existing and used, not implying we create new fasteners all the time, just using what we already have selecting the best for the application.

 

[KnurledNut]

Cost.

 

[C lectric]

I have run into applications where a 12 pt bolt and wrench are needed to be able be able to remove the bolt one 12 pt at a time.
The other is on my boat and the 6 point drive was being chewed up by my 12 pt socket, a good one, but the 6 pt socket stopped the chewing.

 

[KnurledNut]

you cannot use a torx bit in a hex fastener

Now hang on just a dang minute. You see...

 

[whateg01]

I thought the reason for 12 pt fasteners was often because it can be stuffed in a smaller space. Not because it allows higher torque.

 

[_brian_]

I thought the reason for 12 pt fasteners was often because it can be stuffed in a smaller space. Not because it allows higher torque.

I think it is both. You can apply more torque to the 12 point, avoiding the need for the larger head, allowing you to place it in a tighter space. I am no expert though, I asked the question so I can hear what others know on the topic. I personally like the grip achieved with 12 point fasteners, but I also like the grip on external torx. I do understand the issues they cause, it holds true (I think) that every fastener type has its pros and cons, and should be used where the pros can be a benefit and the cons can be avoided as much as possible.

I have not experienced many 12 point fasteners in the 20+ years I have worked on cars. Axle nuts are the most common for me. I made this thread because I had heard the 12 point fastener was gaining some momentum in vehicle applications, but have nothing to really support this. It made me think of the reasoning and logic of fasteners again. Unlike the use of fasteners like etorx, torx, triple square (XZN), etc... the 12 point fastener is something that most people can accommodate with their tools. Most combination wrenches are 12 point, and at least when I Was buying my initial tools, all sets had 12 point sockets, more than the 6 point. I still have 6 point gaps in some of my socket sets, especially the smaller 1/2 drive.

 

[qqzj]

This, would hate to see a 12 point suspension bolt in the rust belt / north.

Most newer socket and wrench tech is designed around grabbing on the flats of a fastener because the corners are weaker and fail, especially when rusty. 12 points would decrease those flat areas and wouldn't leave much meat to grab onto.

This is the best answer. The rust argument comes second. Even interior bolts are 6 points

 

[RedneckWelder]

Paper doesn’t always translate to real life well. 12 pt rounds off easier.

Engineers also love Allens and torx which also **** when conditions aren’t perfect.

 

[AA/FC]

Good luck getting every manufacturer world wide to agree to only using 12 point fasteners. lolol

 

[dnschmidt]

Cost will be an issue as 12 point fasteners are always used on very high end applications such as cylinder head bolts (Subaru) and connecting rod bolts (a lot of people). Both of these are high end and high cost fasteners. Normal grade 5 bolts are not made with the precision or steel of these premium products.

 

[nbpt100]

I can't add much new to this topic except this. The hex head cap screw can take plenty of torque. In fact you will shear off the shank of the screw before you will strip the hex head on most smaller sizes. However when you introduce rust, a worn out tool or an unskilled user, then all bets are off. Those are the wild cards.

So the problems are Rust, old worn out or poor quality tools, and people who are not paying attention or do not understand what they are doing.

A new 12 Pt screw may handle more torque but it does it need to?. It does offer more engagement angles so that is a possible benefit and in an assembly line envirenment it may be of benefit as is Torx.

I like working with Hex Head or Torx fasteners. But not if they are rusty.

 

[finn]

We do, there are select applications on cars that use the 12pt

Example would be ford drive flange at the rear end

Ford driveshaft fasteners have been 12 point, I think, for around forty or so years. I don’t recall having any issues removing them, and I live in a road salt intensive area.

 

[JradM]

I think this suggestion solves a problem that doesn't exist. E.g. a 12pt may be "superior" in how much torque it can handle, but generally those same fasteners are working just fine with a 6pt.

If it offers a benefit that isn't necessary in most applications, but is also more costly to produce... that's probably enough explanation.

 

[finn]

12 point is generally superior for automated assembly. Easier /faster indexing, with superior assembly tool life.

 

[Bad Eye Bill]

Ford driveshaft fasteners have been 12 point, I think, for around forty or so years. I don’t recall having any issues removing them, and I live in a road salt intensive area.

Lots of salt here too. I changed the transmission in my '97 F150 4x4 a few years back. Put in a used one out of a junker. Every 12 point fastener on those driveshafts were either rusted to a point or shortly after attempting to turn them they were converted to a point.

Torched the heads off, removed shafts then turned them out with vice grips. Got new ones from a transmission shop.

Wasn't impressed at all.

 

[finn]

Lots of salt here too. I changed the transmission in my '97 F150 4x4 a few years back. Put in a used one out of a junker. Every 12 point fastener on those driveshafts were either rusted to a point or shortly after attempting to turn them they were converted to a point.

Torched the heads off, removed shafts then turned them out with vice grips. Got new ones from a transmission shop.

Wasn't impressed at all.

Yea. Twenty six years old is probably on the downside of the life expectancy on something like this.

Especially in New Brunswick.

it’s probably safe to assume that ease of assembly would be higher on the design requirements list than ease of disassembly twenty six years after the fact, in a junkyard in NB, no less.

I don’t recall any issues doing shaft removal on rusty 80’s broncos or Mustangs.

 

[ybnormal]

You ever try to use an adjustable wrench on a 12 point fastener?

it's a poor craftsman that blames his tools...

 

[ybnormal]

Engineers also love Allens and torx which also **** when conditions aren’t perfect.

because, of course, they don't lie down with their pocket protectors on the floor of the engineering lab in 40degree weather to work on rusty fasteners

 

[dchawk81]

You ever try to use an adjustable wrench on a 12 point fastener?

That's why God invented vise grips.

 

[dchawk81]

I'd be much harder to make a rounded off rusty 9/16 head to 1/2 with a file.

Dremel you some new notches and finally use that 5.5mm.

 

[F-22]

My knipex wouldn't work on 12pt

Cobras surely would

 

[Bad Eye Bill]

Yea. Twenty six years old is probably on the downside of the life expectancy on something like this.

Especially in New Brunswick.

it’s probably safe to assume that ease of assembly would be higher on the design requirements list than ease of disassembly twenty six years after the fact, in a junkyard in NB, no less.

I don’t recall any issues doing shaft removal on rusty 80’s broncos or Mustangs.

There's no question about that. That assumption applies to many things. The donor truck wasn't in a junkyard, I bought it from a guy who quit running it due to it not being able to pass the MVI.

I've removed hex head bolts in similar situations with much less difficulty.

 

[nbpt100]

because, of course, they don't lie down with their pocket protectors on the floor of the engineering lab in 40degree weather to work on rusty fasteners

It is more influence from the MBA's than the Engineers. BTW they dont wear pocket protectors any more.

 

[jrsavoie]

It would be overkill making all fasteners 12 point, where it's required auto manufacturers do utilise 12 point (mostly torqùe critical internal engine components like con-rod bolts etc.)

Using them under the car exposed to road salt etc. Is a really bad idea as has been suggested.

I think using 12 point for critical fasteners maybe "encourages" techs to actually torque critical fasteners to spec, rather than just blasting them with an impact wrench (please don't judge me )

I've seen a lot of stuff messed up due to people being too lazy to look up the torque and get out a torque wrench.
I've been the victim more than once.

I avoid touching the 12 point stuff. I've seen way to many 6 point fasteners rounded off