Is there a way to fix these clamps?

[WobblyHand]

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 I don't think much of anything is made of malleable iron anymore, it has been replaced by ductile iron, which is much cheaper to produce.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

 

[Bi11Hudson]

I don't think much of anything is made of malleable iron anymore, it has been replaced by ductile iron, which is much cheaper to produce.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

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.

 

[WobblyHand]

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?

 

[woodchucker]

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.

 

[woodchucker]

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 404050View 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...

 

[WobblyHand]

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

 

[woodchucker]

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...

 

[mickri]

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.

 

[cathead]

Mine ended up as hold downs on a welding table