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Which is the Stronger Breaker Bar Design?

Charles (in GA)

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Title says it all.

I know there were patent infringement lawsuits involving the clevis on handle vs clevis on square drive, back in the 1930's. From Alloy Artifacts P&C page..... "During the 1930s P&C continued to expand its automotive and aviation tool business, although this period may have seemed quiet in comparison with the drama of the late 1920s. One interesting event did occur though, when P&C was sued for patent infringement by Samuel Eagle, the inventor of a design for flex-head (or "hinge") handles used by Plomb. Eagle had received patent #1,380,643 in 1921, and Plomb had offered tools in this design since the late 1920s. (See for example the Plomb DTH Hinge Handle.)

P&C had also offered flex-head handles since the 1920s, but in a slightly different design with the fork on the flex head, rather than on the handle. The flex-head handles became a very popular tool, and at some point in the early 1930s P&C began offering flex handles in the Eagle design as well. (P&C referred to their original design as "Outside Head" models, with the Eagle design as the "Inside Head" version.)

In the early 1930s Samuel Eagle filed a patent infringement lawsuit against the P&C Hand Forged Tool Company, but in a 1935 decision (Eagle v. P&C Hand Forged Tool Co., 9 Cir., 74 F.2d 918, 920) the court found in favor of P&C. The court determined that the Eagle patent was invalid based on claims in several different prior patents, and this case has been cited in later patent infringement cases as a precedent. "


But this is long overwith, patents expired, etc................................

So, Which is stronger and why??????????????????/

Charles
 

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Monte

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i don´t know :) but maybe there is a difference in material thickness ?

snap-on, Matco, Mac, Ko-Ken, Stahlwille, Gedore, Hazet use the design on the left for example. No explanation, but maybe it is the explanation which design is stronger :)
 

Flash21

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snap-on...use the design on the left for example. No explanation, but maybe it is the explanation which design is stronger :)

Doesn't Snap-On sell both versions, straight and 45 degree?
 

Indy_500

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the one on the right imho is stronger. I no longer use my daddy's snap on breaker bar because the last time i did i snapped off about a half dozen bolts on my snowmobile. I'll stick to my long HF because it has some "bend" in it so it dont' snap so easily
 

mrholeshot

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Just depends on the steel used. I've seen both type in good and bad. The Craftsman in the left is among the weakest breaker bars made. They sheer at the top of the socket. There is not enough beef below the pivot point.
 

mrholeshot

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the one on the right imho is stronger. I no longer use my daddy's snap on breaker bar because the last time i did i snapped off about a half dozen bolts on my snowmobile. I'll stick to my long HF because it has some "bend" in it so it dont' snap so easily

That long HF is a super breaker bar. Even better because it's cheap
 

shotgunfatcat

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the one on the right imho is stronger. I no longer use my daddy's snap on breaker bar because the last time i did i snapped off about a half dozen bolts on my snowmobile. I'll stick to my long HF because it has some "bend" in it so it dont' snap so easily

That is the first time I heard someone happy about their tools bending.....

Wait till it snaps and you get a 1/2 rod stuck in your side.
 
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C

Charles (in GA)

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Not asking about brands or materials, just designs. To me, the Cornwell bar on the right LOOKS weaker. I know Snap On makes the breakers with the removable handles that are like the Cornwell, clevis on the square drive.

I would think the clevis on the handle would be a stronger design. You cannot put that much material in the clevis on the square drive, it would be too bulky.

Any engineers want to analyze the stresses involved?

Charles
 

supertooljunkie

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Just depends on the steel used. I've seen both type in good and bad. The Craftsman in the left is among the weakest breaker bars made. They sheer at the top of the socket. There is not enough beef below the pivot point.

I bet I have broken 20-25 Cman breaker bars like that. I broke five in one day removing the rear brake drum on an air cooled VW. The tool people at Sears were not happy with me.:bounce:
 

Indy_500

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That is the first time I heard someone happy about their tools bending.....

Wait till it snaps and you get a 1/2 rod stuck in your side.

haha i like to call it the flexible breaker bar it still works great but when something is torqued 100+ ft lbs u can feel it flex a little because its soooo long
 

mrholeshot

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Any engineers want to analyze the stresses involved?

Charles
If the style on the right has a tool steel bolt it will be stronger. The end flares out so no loss of metal and the bolt keeps the end from speading. The one on the left has a square design socket attachment point that doesn't increase in size in the pivot point. This would be the weak spot and the reason so many Craftsman breaker bars fail. Take the same design and let the socket attachment point move into a larger point between the pivot and it could increase the strength. Again the strength of the metal makes all the differance.
 

Tatsuya

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That long HF is a super breaker bar. Even better because it's cheap
For sure. I like how it can flex to less than 90 degrees. Helped me a bunch the other day taking off torque plate bolts when checking my rotors, which are scored to ****. Clears the wheel well, didn't have to get under the car even with the 25" long bar.
 
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Charles (in GA)

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SO make 24" long breaker bars with 45 degree offset square but it's the same design as all their other bars with the clevis on the handle.

http://buy1.snapon.com/catalog/item...id=349&supersede=&store=snapon-store&tool=all

They do make the clevis on the square drive on some types. These take interchangeable handles of varying lengths.

http://buy1.snapon.com/catalog/item...7&group_ID=424&store=snapon-store&dir=catalog

28464.JPG


Charles
 

Packard V8

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Worried about breaking the flex head on your 1/2" breaker bar? I've solved that problem. This bad boy has no flex joint.

PICT0006.JPG



It's an old PA Sturdevant 3/4" 300 #/ft 34"-long torque wrench.

PICT0003.JPG


PICT0005.JPG


I picked it up the other day for $5, just in case I ever need some length and leverage beyond what the long Snap-on bar can handle. I hope never to work on anything this won't break loose and nobody is strong enough to break it.

jack vines
 
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matthew

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In general I would think the pin is the weakest part. So as long as the pin is the same diameter, the same material, and the width of the forked part is the same, then the strength is the same, because the shear applied to the pin would be the same.
 

wafrederick

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Most have done away with the pin.I know Mac,Snap On and Matco have done way with the pin using a bolt design.Craftsman still uses the pin design,the pin will slide out very easily.Mac used to use the design on the right.
 

caper

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I've broken quite a few of the design on the left.Have never used the design on the right.I've never had one break a pin,always an ear off the bar end.
 

Packard V8

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Most have done away with the pin.I know Mac,Snap On and Matco have done way with the pin using a bolt design.Craftsman still uses the pin design,the pin will slide out very easily.Mac used to use the design on the right.

Mechanically, the bolt is a pin retained by threads rather than the former press fit. Doesn't appear to be any stronger in shear. What it might do is give the yoke strength to resist spreading.

jack vines
 

bgott

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I bet he broke those five breaker bars by hanging the bars with a socket on the drum nut and then backing the car up with the bar on the ground. ;)
 

djb2

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I recently bought the H-F 25" breaker bar. Basically because it was for a one time use, and it was cheaper than buying a pipe.

I found that it had an unexpected feature: the square drive was offset 12 or 15 degrees, doubling the opportunity to put the bar in a horizontal position. It is much easier getting a nice bouncing rhythm on a horizontal bar than one at an angle. The bar handled 200lb (perhaps a little more) with a very vigorous bounce on the very end of its 25 inches.
 

tjmonsen5

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I actually like my Ace Hardware breaker bar alot! Its round a comfortable to use, unlike the raised panel style of craftsman. I bought the breaker bar before i was educated about tools or ever joined this site. The Ace bar has broken loose every bolt ive ever thrown at it with no troubles.
 

oldtools

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I owned both HF and cman breaker bars. I have not broken either, but I have to say the HF look and feel better. My brother-in-law (he is 180 lbm) was jumping on my 25" HF breaker bar trying to loosen the axle nut. The nut won't come loose, but the breaker bar didn't break either. Its kinda scary watching him jumping on it. I also have Snap On, Williams, Proto, Wright, Plumb, SK, Thorsen, and Armstrong breaker bars, but I use HF the most.
 

haloghalog

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I don't agree with folks talking about breaking the bars, in my opinion they were most likely using the wrong size tool for the application. My Cman 1/2" and HF 1/2" breaker bars are used only for lug nuts and they have both done just fine. Now if you are trying to remove a 34mm axle nut torqued at 220 ft-lbs then you really shouldn't be using 1/2" breaker. With experience you began to recognize what size breaker you should go to and that's why I keep a 3/4" breaker handy, anything at or above 30mm I go to the 3/4" and in some cases if it's seized or rusted I would even use it on lugs nuts.
 

mrholeshot

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. Now if you are trying to remove a 34mm axle nut torqued at 220 ft-lbs then you really shouldn't be using 1/2" breaker..

If a 1/2 breaker bar won't stand 220lbs of torque it's junk. Realisticly it should stand 500ftlbs at the head. I have a 1/2 Harbor freight ratchets that can do that. Even a sorry Craftsman can take 220ftlbs. They were not designed to just do lugnuts
 

mrholeshot

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supertooljunkie is that strong, he kills 5 breaker bars a day
I can snap a Craftsman 1/2 breaker bar in one quick movement with it chucked up in the vice. I can do that sitting in a wheelchair. I'm 6'2 340lbs but I'm no Charles Atlas.
 
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