# Is there a way to fix these clamps?



## WobblyHand (Apr 13, 2022)

Seems I have managed to inherit a bunch of old c-clamps.  Think they came from my maternal grandfather.  I have four "Brink & Cotton" c-clamps that seem to have been sprung.  They were either the Harbor Freight of their day, or they may have been abused past their limit.  They seem to be marked as malleable or ductile iron.  Is there anyway to fix these clamps, or should they be scrapped or repurposed?  Have a bunch more clamps, most Brink & Cotton but some Cincinnati.  Most are acme threaded but a few are 60 degree threads.  Here are two of them.  I could have sworn one had some cracks, but can't seem to find that one.



It's not like I need them, but, it would be good to fix them, or have them find new homes.  Are they fixable?  Or is that a fool's errand?


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## jwmelvin (Apr 13, 2022)

I’d try heat shrinking the inside edge if you have an oxy-fuel torch.


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## WobblyHand (Apr 13, 2022)

jwmelvin said:


> I’d try heat shrinking the inside edge if you have an oxy-fuel torch.


So the top inside corner or where?  Or do you mean literally the raised inside surface facing the screw?  Guess, I'm not sure where you mean.  Have oxy-acetylene, so heat is not a problem.


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## jwmelvin (Apr 13, 2022)

Heating the metal sufficiently and then cooling it will cause it to shrink. So you want to do that where shrinking will pull the structure into your desired alignment. I’d do it here:


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## WobblyHand (Apr 13, 2022)

jwmelvin said:


> Heating the metal sufficiently and then cooling it will cause it to shrink. So you want to do that where shrinking will pull the structure into your desired alignment. I’d do it here:


Thanks.  I'll give it a try.


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## benmychree (Apr 13, 2022)

Heating malleable iron and quenching it is liable to alter the physical characteristics of the metal, not to the good; generally, sprung clamps are not worth messing with ---


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## Bi11Hudson (Apr 13, 2022)

Mallable iron is very close to what we today know as steel. Heating and then coolong will be likely the best solution. "C" clamps were meant to hold two pieces together as the were more permanantly attached. They were never intended for, but often used for, making temporary repairs or shaping parts. Heating sprung clamps will (most likely) restore the general shape. But the ability to clamp will be greatly reduced. 

.


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## WobblyHand (Apr 13, 2022)

Bi11Hudson said:


> Mallable iron is very close to what we today know as steel. Heating and then coolong will be likely the best solution. "C" clamps were meant to hold two pieces together as the were more permanantly attached. They were never intended for, but often used for, making temporary repairs or shaping parts. Heating sprung clamps will (most likely) restore the general shape. But the ability to clamp will be greatly reduced.
> 
> .


I was under no illusion that they would be good as new afterwards.  Maybe they would have some minor utility, or maybe not.


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## WobblyHand (Apr 13, 2022)

benmychree said:


> Heating malleable iron and quenching it is liable to alter the physical characteristics of the metal, not to the good; generally, sprung clamps are not worth messing with ---


Thanks for your assessment.  Sometimes I get carried away trying to save something that really may not be worth the effort.  Might try one for the heck of it, but am not expecting as new any performance.  Think these clamps were sprung before I was born.


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## benmychree (Apr 13, 2022)

WobblyHand said:


> I was under no illusion that they would be good as new afterwards.  Maybe they would have some minor utility, or maybe not.


It is my understanding that malleable iron (if the clamps are truly just that) is white cast iron (very hard and brittle) that is annealed over a long period to make it some sort of a cousin of steel, heat and quench is liable to make it brittle again.  I don't think much of anything is made of malleable iron anymore, it has been replaced by ductile iron, which is much cheaper to produce.


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## WobblyHand (Apr 13, 2022)

benmychree said:


> It is my understanding that malleable iron (if the clamps are truly just that) is white cast iron (very hard and brittle) that is annealed over a long period to make it some sort of  cousin of steel, heat and quench is liable to make it brittle again.  I don't think much of anything is made of malleable iron anymore, it has been replaced by ductile iron, which is much cheaper to produce.


Oh, that is good to know.  Don't think I will bother with the malleable clamps then.  Seems like it would be a waste of torch gas.

Some of the c-clamps I have are marked (cast letters) as ductile iron.  Are ductile iron clamps treatable?  

Plumbers who used to install steam heat systems used to prefer malleable iron fittings because they could break and remove them easily.  Made repairs easy.  Now that there are power threaders and power saws, the need for malleable fittings has diminished.  And yes, the ductile fittings were a lot cheaper.


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## Bi11Hudson (Apr 13, 2022)

benmychree said:


> I don't think much of anything is made of malleable iron anymore, it has been replaced by ductile iron, which is much cheaper to produce.


Not sure about other objects, but there are several foundries here that still produce mallable iron for pipe.

*EDIT*: I was thinking of "ductile iron", not mallable iron. Senility sneaks up on me sometimes.
.


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## benmychree (Apr 13, 2022)

WobblyHand said:


> Oh, that is good to know.  Don't think I will bother with the malleable clamps then.  Seems like it would be a waste of torch gas.
> 
> Some of the c-clamps I have are marked (cast letters) as ductile iron.  Are ductile iron clamps treatable?
> 
> Plumbers who used to install steam heat systems used to prefer malleable iron fittings because they could break and remove them easily.  Made repairs easy.  Now that there are power threaders and power saws, the need for malleable fittings has diminished.  And yes, the ductile fittings were a lot cheaper.


I do know that ductile iron is (at least sometimes) heat treated post casting.  It comes in many different classes of physical characteristics, some high ductility, some high strength, some in the mid range; I used to have two throw crankshafts made of 100-70-03 ductile for marine steam engines that I made and sold years ago, the 100 is tensile strength, the 70 is yield, the 03 is elongation.  Even at that tensile strength, the metal machines nicely and easily and grinds to a nice surface finish.  Ductile is an alloy cast iron with nickel and other ingredients including steel scrap and coke for carbon, it is melted, and poured into a narrow deep ladle on top of magnesium; the ensuing reaction changes the structure from spherical to nodular (rod shaped), this gives the metal its ductility; castings are poured within a certain time limit, as at a certain point, the metal reverts to the spherical form as it was before the reaction.


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## WobblyHand (Apr 13, 2022)

benmychree said:


> I do know that ductile iron is (at least sometimes) heat treated post casting.  It comes in many different classes of physical characteristics, some high ductility, some high strength, some in the mid range; I used to have two throw crankshafts made of 100-70-03 ductile for marine steam engines that I made and sold years ago, the 100 is tensile strength, the 70 is yield, the 03 is elongation.  Even at that tensile strength, the metal machines nicely and easily and grinds to a nice surface finish.  Ductile is an alloy cast iron with nickel and other ingredients including steel scrap and coke for carbon, it is melted, and poured into a narrow deep ladle on top of magnesium; the ensuing reaction changes the structure from spherical to nodular (rod shaped), this gives the metal its ductility; castings are poured within a certain time limit, as at a certain point, the metal reverts to the spherical form as it was before the reaction.


Pardon my lack of knowledge, are you saying that ductile iron also is not a good candidate for simple heating and quenching for a sprung clamp?


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## woodchucker (Apr 13, 2022)

I have Brinks and Cotton, they seem to be pretty good quality. Much better than todays quality. The swivel foot is awesome compared to a bessey or other modern clamp. I would try to fix. if it doesn't hold, you have not lost much. If it does, fantastic.

I had a friend who held his trailer together with ONE . he asked me to weld it, I have to say I was surprised that one clamp held it together because when we took the clamp off the thing fell apart on that side.


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## woodchucker (Apr 13, 2022)

WobblyHand said:


> Seems I have managed to inherit a bunch of old c-clamps.  Think they came from my maternal grandfather.  I have four "Brink & Cotton" c-clamps that seem to have been sprung.  They were either the Harbor Freight of their day, or they may have been abused past their limit.  They seem to be marked as malleable or ductile iron.  Is there anyway to fix these clamps, or should they be scrapped or repurposed?  Have a bunch more clamps, most Brink & Cotton but some Cincinnati.  Most are acme threaded but a few are 60 degree threads.  Here are two of them.  I could have sworn one had some cracks, but can't seem to find that one.
> View attachment 404050
> View attachment 404051
> 
> It's not like I need them, but, it would be good to fix them, or have them find new homes.  Are they fixable?  Or is that a fool's errand?


how's that screw on the right? looks a little screwed...


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## WobblyHand (Apr 13, 2022)

woodchucker said:


> how's that screw on the right? looks a little screwed...
> View attachment 404067
> View attachment 404068


Not sure if you are referring to your pictures or mine?  If yours, the screw on the Left is plated and thinner than on the two B&C clamps.


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## woodchucker (Apr 13, 2022)

WobblyHand said:


> Not sure if you are referring to your pictures or mine?  If yours, the screw on the Left is plated and thinner than on the two B&C clamps.


I was showing the B&C's 2 of them, notice how poor the bessey stacks up to them. The one you are referring to on the left is a current bessey... crap.  I would try to fix the B&C's I have more in my garage of the B&C's. I think they are good quality. Mine don't say ductile.. so I am not sure if they are older, younger...


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## mickri (Apr 13, 2022)

I got a milk crate full of C-Clamps at an auction awhile back.  Some were bent way worse than yours.  I snugged them up in a vice and bent them back into shape.  No heat.  Took a bit of force.


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## cathead (Apr 13, 2022)

Mine ended up as hold downs on a welding table


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## mmcmdl (Apr 13, 2022)

I had 2 of my biggins over the neighbors the other day trying to lift a large concrete pipe out of the ground . Bobcat and the Kubota and large chains didn't budge it , but the clamps held great .   Jack hammer did the trick .


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## Janderso (Apr 13, 2022)

Nothing wrong with repurposing compromised clamps when you can.
These two clamps came out of the ash pile of our house fire. 
They were Bessey clamps once. Now?
They work to secure stuff to my work table


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## brino (Apr 13, 2022)

Been there done that!
https://www.hobby-machinist.com/threads/straightening-a-c-clamp.39484/post-338748

I found that my clamps were easy to straighten. No heat required.
I was concerned about breaking or weakening them, but I learned that they should be on the soft side to keep them from shattering in regular use.

Brian


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## WobblyHand (Apr 13, 2022)

brino said:


> Been there done that!
> https://www.hobby-machinist.com/threads/straightening-a-c-clamp.39484/post-338748
> 
> I found that my clamps were easy to straighten. No heat required.
> ...


You have given me some hope that the clamps are repairable.  I will try bending one.  Worst case, I will make a hold down clamp like @Janderso or @cathead have shown.  Welding table hold downs are a good thing to have!


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## woodchucker (Apr 13, 2022)

WobblyHand said:


> You have given me some hope that the clamps are repairable.  I will try bending one.  Worst case, I will make a hold down clamp like @Janderso or @cathead have shown.  Welding table hold downs are a good thing to have!


Well Jeff's clamp is a sliding F style clamp. yours is a C clamp. not really workable for that.


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## WobblyHand (Apr 13, 2022)

woodchucker said:


> Well Jeff's clamp is a sliding F style clamp. yours is a C clamp. not really workable for that.


Oh, don't be so literal .  I know.  The point was to repurpose the clamp, and Jeff did it well in my book.  cathead did a nice job too.


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## woodchucker (Apr 13, 2022)

WobblyHand said:


> Oh, don't be so literal .  I know.  The point was to repurpose the clamp, and Jeff did it well in my book.  cathead did a nice job too.


well hey, I couldn't tell after you took my bessey as an example of (I don't know  what) I was just trying to show you , you have a superior product...

so I guess I was spoon feeding you...


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## WobblyHand (Apr 13, 2022)

woodchucker said:


> well hey, I couldn't tell after you took my bessey as an example of (I don't know  what) I was just trying to show you , you have a superior product...
> 
> so I guess I was spoon feeding you...


Guess you were.    Sometimes I don't always pick up the clue phone.  Humor and subtlety don't always convey correctly in written form.  And, yes, sometimes things do go right over my head.


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## benmychree (Apr 13, 2022)

WobblyHand said:


> Pardon my lack of knowledge, are you saying that ductile iron also is not a good candidate for simple heating and quenching for a sprung clamp?


In a word, yes --- I do not think heating would be a problem, but quenching very well could be a problem.
Over the year, I have collected quite a few clamps, I try to stay away from the sort of clamps pictured and keep on the lookout for such as Williams or Armstrong forged steel clamps.


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## woodchucker (Apr 13, 2022)

benmychree said:


> In a word, yes --- I do not think heating would be a problem, but quenching very well could be a problem.
> Over the year, I have collected quite a few clamps, I try to stay away from the sort of clamps pictured and keep on the lookout for such as Williams or Armstrong forged steel clamps.


yea, I could see that for a machinist. But those are monster clamps. I have one, and it weighs about 3 of the B&Cs


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## jwmay (Apr 13, 2022)

WobblyHand said:


> Sometimes I get carried away trying to save something that really may not be worth the effort.


Story of my life....err garage/shop tool scavenging life at least.


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## Provincial (Apr 14, 2022)

I bought a pair of 6" Brink & Cotton C-clamps from the local hardware store almost 50 years ago.  While I try not to abuse my tools, these two clamps have done everything I have asked of them, and show no wear of deformation.  They are not as heavy-duty as my Williams and Armstrong clamps, but they are plenty strong for all but extreme tasks.


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## Janderso (Apr 14, 2022)

benmychree said:


> Armstrong forged steel clamps.


I have a pair of StrongHand clamps. I thought they were Armstrongs??
I'll have to check them out.
These StrongHand clamps are the real deal. With a price tag to match!


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## ericc (Apr 14, 2022)

I have a small, cute C-clamp that I bought at a garage sale.  The owner must have made a custom fixture or something, since there was a hole drilled in the frame.  When I clamped something, the frame cracked at the hole, and the clamp bent.  I bent it back, but it was was flimsy due to the fatigue.  Cast iron cannot take much bending.  I had heard about cast iron welding rod, and wanted to repair it, but it seems to be hard to find.  Somebody was selling a few sticks on Ebay for $80.  Too much.  So the lousy clamp went into the to-do box until I found a shard of cast iron from a shattered drain cover in the street.  I used an oxy-propane torch, and it flowed in like "buttah".  It was a good strong repair, but the decarburized zone became susceptible to rust.  Another one of those "stupid metal tricks". 

Anyway, cast iron cannot take much bending, heat or no heat.  A forged steel clamp is much more forgiving.


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## woodchucker (Apr 14, 2022)

Janderso said:


> I have a pair of StrongHand clamps. I thought they were Armstrongs??
> I'll have to check them out.
> These StrongHand clamps are the real deal. With a price tag to match!


That's no stinkin Armstrong... 
Now this is an ArmStrong, and legstrong, and just beefy strong.
talking the middle guy... hand for sizing... Never let one of these drop on your foot.


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