6 point vs 12 point

[Dick in Wisconsin]

Why 6 point and 12 points nuts and bolt heads?

Does one have an advantage over the other?

Thanks!

 

[n8n]

12 point - easier to put on bolt heads, required for 12 point fasteners (usually "high performance" hardware e.g. ARP)

6 point - less likely to round off a bolt head or nut when corroded or overtorqued.

For general use I would probably only bother to have 6 point sockets and drag out the 12 points only when specifically needed. Oddly many "mechanic's sets" sold at e.g. Sears, Lowe's, etc. seem to have 12 point sockets and I'm not sure why.

Either will probably be fine on a near-new car in good condition, but if you work on old project cars...

 

[Moose-LandTran]

It makes guys like me buy both sockets, which leaves less space in my toolbox, and reduces the amount of air in there that collects condensation and causes rust on tools when the woskshop changes temp in the colder months.

So there you go, it's all about reducing corrosion.

 

[W0rLDWaR4]

I have both..the 12pts just usually take up space in my box. Hardly, if ever, they get used.

 

[Big Pete]

12 point fasteners are usually made of pretty decent stuff, so can get away with a smaller head, and still cope with big torques. They have their moments when space (or weight) is tight like on aircraft. They are a lot pricier to manufacture though,, 6 point ofasteners can be blasted out cheap, even in decent steel.

 

[Outlawmws]

It makes guys like me buy both sockets, which leaves less space in my toolbox, and reduces the amount of air in there that collects condensation and causes rust on tools when the woskshop changes temp in the colder months.

So there you go, it's all about reducing corrosion.

I approve of this theory!

 

[Wakefield]

There have been many topics about this-
I think if not rusted then 12 point box or socket on a 12 point fastener can handle more stress than a 6 point on a hex fastener-
A six point box or socket on a hex should handle more than a 12 point on it-but quality 12 point tools on steel hex fasteners in good condition should work perfectly adequate,especially when dealing with large size fasteners
and of course 12 point wrench on hex fastener gives you shorter arc swing to get another bite
noticed in one of the tool catalogs that it said not to use 12 point impact socket on 6 point fastener with impact power-? so that all of the points share the stress instead of just half of them?

 

[Outlawmws]

12 point - easier to put on bolt heads, required for 12 point fasteners (usually "high performance" hardware e.g. ARP)

6 point - less likely to round off a bolt head or nut when corroded or overtorqued.

For general use I would probably only bother to have 6 point sockets and drag out the 12 points only when specifically needed. Oddly many "mechanic's sets" sold at e.g. Sears, Lowe's, etc. seem to have 12 point sockets and I'm not sure why.

Either will probably be fine on a near-new car in good condition, but if you work on old project cars...

I have both..the 12pts just usually take up space in my box. Hardly, if ever, they get used.

There have been many topics about this-
I think if not rusted then 12 point box or socket on a 12 point fastener can handle more stress than a 6 point on a hex fastener-
A six point box or socket on a hex should handle more than a 12 point on it-but quality 12 point tools on steel hex fasteners in good condition should work perfectly adequate,especially when dealing with large size fasteners
and of course 12 point wrench on hex fastener gives you shorter arc swing to get another bite
noticed in one of the tool catalogs that it said not to use 12 point impact socket on 6 point fastener with impact power-? so that all of the points share the stress instead of just half of them?

Guys, he's asking about the fasteners this time, not the tools for them...

 

[n8n]

Damn, you're right, reading comprehension FAIL.

I believe, that size for size, a 12 point head used with a 12 point socket or box wrench is stronger/more resistant to rounding than is the same size 6 point used with a 6 point socket or box wrench. So the size of the head can be reduced for tight clearance applications. Also easier to get the socket on the fastener head for assembly.

 

[Farmall450]

Damn, you're right, reading comprehension FAIL.

I believe, that size for size, a 12 point head used with a 12 point socket or box wrench is stronger/more resistant to rounding than is the same size 6 point used with a 6 point socket or box wrench. So the size of the head can be reduced for tight clearance applications. Also easier to get the socket on the fastener head for assembly.

+1 I believe so.
I also was about to have a snotty reply for yet another "6 vs 12 point" thread.

 

[Dick in Wisconsin]

Guys, he's asking about the fasteners this time, not the tools for them...

Thanks!

Why would an engineer spec a 12 points fastener vs. 6 point fastener?

Will the 12 point take more stress?

Thanks!

 

[ex-x-fire]

If the 12 pt fastener was never invented, then I wouldn't see the point in 12 pt sockets.
In the automotive world I could count on one hand which 12pt sockets that get used on 12pt fasteners.

 

[brettboat]

12 point - easier to put on bolt heads, required for 12 point fasteners (usually "high performance" hardware e.g. ARP)

6 point - less likely to round off a bolt head or nut when corroded or overtorqued.

For general use I would probably only bother to have 6 point sockets and drag out the 12 points only when specifically needed. Oddly many "mechanic's sets" sold at e.g. Sears, Lowe's, etc. seem to have 12 point sockets and I'm not sure why.

Either will probably be fine on a near-new car in good condition, but if you work on old project cars...

That sums it up in a nutshell. Good job. I tend to go for 6 point unless I'm in a real tight spot... OR turbine engines, they're all 12 point hardware.

 

[Givl Reggin]

Why would an engineer spec a 12 points fastener?

More torque with a smaller head vs. moving up to the next size 6-point.

 

[tbaggz]

Main reason for 12Pts is high speed assembly.

 

[RECox286]

In my experience, I have found that 12 pt fasteners

have more applications in aircraft than in any other

machine I have worked on. As to stronger, able to

withstand more stress, I don't know, b/c most torque

on aircraft fasteners is in inch pounds, the exceptions

being mostly engine mounts or other engine related items.

Uncle Bob

 

[brettboat]

Main reason for 12Pts is high speed assembly.

They can take alot more torque! Like 25-30%

 

[Moose-LandTran]

They can take alot more torque! Like 25-30%

I suppose they have twice the contact area.

 

[Bigblue&Goldie]

They are used a lot in aviation and motorsports. The hardware is generally rated for higher torque levels than grade 8 hardware. I personally like them, but they are too expensive for my blood. I keep a basic set of 12pt sockets for them as I occasionally run into them.

 

[pendragon1998]

Why don't we have a sticky thread for all aspects of the 6 vs. 12 debate and just be done with it?

 

[brettboat]

I suppose they have twice the contact area.

No idea. I just know turbine engines are covered in nothing but 12 point and the hardware is outrageously expensive. Cost for the 1/4x3/4 bolts on the compressor case halfs on a JT12... There's about 100 or so of them. Last time I priced them out, the nut was $75 and the bolt was I think $200.

 

[shockwave]

12 point fastners will handle a lot more torque than the opposite 6 point.

The best example I can use off the top of my head a triple square has a lot more torque to break free instead of the respective internal hex or internal Torx fasteners anyone that works on German cars regularly can tell u how tight a triple square can be

 

[Moose-LandTran]

No idea. I just know turbine engines are covered in nothing but 12 point and the hardware is outrageously expensive. Cost for the 1/4x3/4 bolts on the compressor case halfs on a JT12... There's about 100 or so of them. Last time I priced them out, the nut was $75 and the bolt was I think $200.

What the hell? That's outrageous. There must be a massive mark-up in there, or are they actually that expensive to manufacture?

12 point fastners will handle a lot more torque than the opposite 6 point.

The best example I can use off the top of my head a triple square has a lot more torque to break free instead of the respective internal hex or internal Torx fasteners anyone that works on German cars regularly can tell u how tight a triple square can be

Gawd, i love triple squares!

 

[brettboat]

What the hell? That's outrageous. There must be a massive mark-up in there, or are they actually that expensive to manufacture?

Well all hardware must be certificated for said application. The manufacturer says that only XYZ bolt and XYZ nut is acceptable. For another nut and bolt to be approved you'd need to get it certificated by the FAA... How would you test it? Well you need to come up with that, consult with the FAA and see if they themselves approve the process. 4-10 years later you'll have an approved nut and bolt. Every dime comes out of your pocket. So after about 10,000+ gallons of jet fuel, purposely destroying 4+ engines and who knows what else you'll have it.

So yea, Pratt and Whitney can charge whatever they want.

I destroyed a 1 inch landing gear bolt a few weeks ago that was seized... $125 from Cessna.

 

[Moose-LandTran]

Well all hardware must be certificated for said application. The manufacturer says that only XYZ bolt and XYZ nut is acceptable. For another nut and bolt to be approved you'd need to get it certificated by the FAA... How would you test it? Well you need to come up with that, consult with the FAA and see if they themselves approve the process. 4-10 years later you'll have an approved nut and bolt. Every dime comes out of your pocket. So after about 10,000+ gallons of jet fuel, purposely destroying 4+ engines and who knows what else you'll have it.

So yea, Pratt and Whitney can charge whatever they want.

I destroyed a 1 inch landing gear bolt a few weeks ago that was seized... $125 from Cessna.

That's scary expensive. And i thought it was bad when i have to get handfuls of bolts from VW..

 

[brettboat]

That's scary expensive. And i thought it was bad when i have to get handfuls of bolts from VW..

Welcome to aviation!

 

[Moose-LandTran]

Welcome to aviation!

Nice!

 

[Grimly]

You're also paying for the traceability and the paper trail in any aviation-related hardware. All adds to cost.
Some mark-ups appear unreal, but otoh, I'd rather not be in a plane that develops a dud rudder because somebody cheaped out.

 

[bushmechanic]

I've noticed that 12 point fasteners are more often used on safety-related hardware than 6 point. I think one of the reasons might be interaction between the socket and fastener.

12 point sockets and fasteners must be connected in a more precisely perpendicular manner than their 6 point equivalents, and once connected are far less likely to move in relation to one another.

That forces you to use them properly.

I'm not sure if it's a primary reason for their existence, but engineers are bound to consider that when specifying them.

As for the old 6 versus 12 socket debate, I've got a simple way of looking at it:

Working on my own cars, where I know every fastener is in neigh on perfect condition, I keep 12 point sockets handy for their use on the occasional 12 point fastener, and because they provide easier access.

If I worked on other people's cars, where I was likely to encounter corroded or stuck fasteners frequently, I'd keep 6 point sockets handy. This is useful practice when I buy and sell a car.

 

[nicksnothereman]

Why don't we have a sticky thread for all aspects of the 6 vs. 12 debate and just be done with it?

He's asking specifically about why they'd put a 12 point bolt vs. a 6 point vs. the traditional socket or wrench thread. I think it's related to clearance and torque. 12 point bolts are almost un-strippable at the head (unless you're using the wrong size socket).