Filter in the Fuel Tank

[Casey]

12 point is a far better fit.less chance of slipping

How do you figure that??    It just leaves more cutout spaces that aren't useful.  More chance of stripping.  At least for small tight bolts like the ones holding the fan on the front of the engine, 12-point is often useless and will just make the nuts turn round and useless, without budging.

[Tony66_au]

Well Casey, its like this................

After 32 years of working on cars both professionally and recreationally, Building numerous Rally and a few race cars, Owning a business that specialised repair and modification of sports and muscle cars and often fixing other enthusiasts stuff ups I know this to be true.

Higher point count in a socket means you can apply more torque to the fastener because the load is spread more efficiently over the contact area, they also allow you to work better with damaged or slightly rounded nuts and bolts and they are a far better fit.

And for exactly the same reason why you wouldn't argue that an open ended spanner or shifter is better than a ring spanner...........................

Capish?

[ziper1221]

Are you sure about that? if you look at the pic, you can see how the 6 point has a higher total contact area:

[Casey]

Are you sure about that? if you look at the pic, you can see how the 6 point has a higher total contact area:

Yeah, I see extra space on the left, not on the right.  I have stripped many a rut with 12-point, never once with 6-point.  Experience speaks louder than theory.  The only trouble with 6-point is that if the nut is already fouled up by previous shenanigans then sometimes it doesn't want to fit.  Or sometimes if you have less than 30 degrees of clearance and a ratchet won't fit a 12-point spanner can be handy.

Even with a 12-point socket, only six of the points are going to actually be making contact with the bolt when you apply torque anyways - all 12 won't be in contact at all times.

[JasonP]

After a few minutes of online research, this issue seems to be one of the eternal un-resolved debates. I see a lot of anecdotal evidence, but it would be nice to see some hardcore engineering analysis on which is better on a hex bolt: 6 point or 12 point.

My opinion would be the 6-point, for this reason: the larger the surface area making contact, the less possibility for slippage and rounding of the corners. 12-point may cumulatively have more surface area contact, but alone, each corner would have less resistance to slippage.

I would go with the 6-point. 

[Tony66_au]

Experience eh?

Easy.

Every time I have had to undo a buggered nut or bolt that wouldn't undo with a standard socket it undid with a 12 point.

Which was why I bought them in the first place.

Jason P, an age old myth is that the flat sides of the hex are where the contact surface is on a hex nut.

its a myth because the torque and contact is initially on the points.

As 12 point is common in Mil spec and aviation because of the double hex nuts commonly used and because a 12 point gives more flexibility in tight spaces.

I use them because they work and especially on engine or gearbox builds.

My intro to 12 point double hex tools was from a teng tool rep who used to visit, Teng do a lot of aviation mechanic tools and later the Snap on guy gave me some 12 point to try on a difficult gearbox build.

Due to the twisting or cam action of the socket, most of the torque is applied at or near the corners of the nut or bolt. Under load, the flats of the nut are not touching the socket at all, it is only the surface to surface contact happening in the corners which bears any load. When the corners of a bolt head or nut begin to become worn or damaged, the material the nut is made from can eventually smear or tear under load and create a situation where the corners are effectively "rounded off" and no longer form a crisp shape anymore. When this happens, the nut or bolt can no longer be turned without special repair or extraction tools. Due to the cost that "rounded" heads can have when it involves large equipment which cannot be assembled or disassembled, many efforts have been made to avert this problem. Over the years several different manufacturers have employed use of convex walls and other design improvements to the socket geometry in order to direct the torque farther away from the corners, and towards the thicker, stronger sections of the nut or bolt head; thus reducing the likelihood of rounding off corners of fasteners under high loads. These designs have been met with commercial success, especially in the automotive maintenance and repair sector.

A common misconception is that a 12-point socket is more likely to round off the corners of a nut or bolt than a 6-point socket. In fact, since the torque is applied at the corners of the fastener, the two sockets have the same number of contact points, apply the same amount of torque, and one is no more likely to round off the corners than another. Although extensive industry testing documents this fact the myth persists.

[oversize]

Ford vs Holden?  LOL!  Personally I prefer 6, but that can be annoying in tight spaces.  Maybe it has something to do with the fact that most of my 12s have been cheapies with less than close tolerances, which results in rounded nuts n bolt heads???   

[wacotech]

I am similar:
for cracking off an old nut I ALWAYS use a 6 sided and most of the time i heat the thing up also - not had any problems since i started doing this. Also if the head is 17mm & up I normally use a 1/2 meter bar, the increase torque from the leverage helps also crack it off with the first try. Once the head is damaged thats often when the trouble can start. Always make shure the socket is FULLY seated on the head.

Recently i have been also spraying Steel Rope Grease on all nut & bolt heads to protect them from corrosion but also so they are easier to undo should i need to.

Also on the subject of big nuts! I bought a cheap 3/4" socket set once for another project years ago but have used it for many other tasks since, especially replacing seals & bearings etc. or knocking a bush out etc. Also there is NO flex at all in the bars so for hi torque nuts its unbeatable and will not break with a long metal pipe on it. For this tank filter i could grind flats on the right socket and use a large adjustable wrench (another usefull tool, a 400mm adjustable) with it.

[Casey]

Always make shure the socket is FULLY seated on the head.

That's really the key thing.  I find that the 12-point sockets do NOT stay seated well, and on a tight nut when a lot of pressure is being applied it's the slippage to a bit sideways that causes stripping.  6-points just inhenently stay put better, though as mentioned they can be a bit of a pain if the nut is already dinged up by some previous idiot.

I'll agree that IF you have and keep them both properly squared, 12-point should work equally well.  This is the problem with theory, it isolates things sometimes with unreliable circumstances.

12-points can be nicer in really tight places, but what I'd really prefer where a socket won't fit is 6-point ratcheting wrenches, with ratcheting built into the box end of the spanner.  I don't have any and don't know if they make six-point versions though.

I *do* have 1/4", 3/8", and 1/2" drive ratchet with 84 teeth though, which is really quite nice when there's low clearances for ratcheting, and in general.  They cost a pretty penny ($80 for the 1/2" one), but are totally worth it.  That yields a 4.3° return swing angle!

See http://toolguyd.com/craftsman-premium-ratchet-review/

I don't have any 3/4" drive stuff yet, mainly due to the cost.  I'd really like to get some.

[Casey]

12-points can be nicer in really tight places, but what I'd really prefer where a socket won't fit is 6-point ratcheting wrenches, with ratcheting built into the box end of the spanner.  I don't have any and don't know if they make six-point versions though.

YES!!  They do exist, and made by the highest-quality tool company I know of, Snap-On!  Now I just need to find somebody to buy them through as I don't believe they sell direct to people like me.  This picture is of a 10mm/11mm one:



I know what I want for Christmas...

[Big_Richard]

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[Casey]

Snap-on allows you to download their (138Mb) dogalog and create an account for online purchasing. Its no longer just a supplier for professionals.

I now have book worth reading!

Ooh, it has an iPad native version too.  Fancy.  I'm glad to have it though, I didn't know you could order direct.

Hmm, I see that the six-point ratcheting dual box sockets are available only in 7&8mm, 10&11mm, and 12&13mm sizes, no larger ones (page 115), and it'll cost about $75 for those three tools.  That's okay though, 7, 8, 10 and 13 are some of the most useful sizes on Mercedes, 10 being the only one I can really think of being in difficult to reach places with tight clearances.  I'd quite like a 17&19 though too.

http://buy1.snapon.com/catalog/item.asp?search=true&item_ID=643903&PartNo=RBM78SC&group_id=675012
http://buy1.snapon.com/catalog/item.asp?search=true&item_ID=643651&PartNo=RBM1011SC&group_id=675012
http://buy1.snapon.com/catalog/item.asp?search=true&item_ID=643845&PartNo=RBM1213SC&group_id=675012

[oversize]

And they're probably four times the price in Australia!!!!   

[Big_Richard]

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