Stretch A Wrench

[Scott NC]

  I have a project in mind that would require stretching the middle part of some OLD  wrenches leaving the jaws intact and no hammer marks.  I will be doing other sizes and materials as well if it works.  In the case of the one in the photo I'd like to make it 2' or longer.  If it was evenly heated, say with a rosebud, and pulled on by the business ends, would this even work?  I've never heard of it before.  Most are medium carbon steel from what I can tell.  Some of it will be mild steel.  I'll try it in any case, but was wondering...  I wonder if it would destroy the cross section.  It is 1/4" thick x 1" wide.

[Glenn]

The material for the extra length (2' or longer) must come from somewhere. 

Try  stretching it from a modeling clay wrench first.  

Why not just take a 2' or longer piece of flat bar stock and forge the ends to the nut size you want?

[Scott NC]

  That's a good idea that I always forget.  I figure it will thin out but wonder if it will keep it's shape. I don't want it to look like a round bar with 2 wrench ends.  Thanks, I must buy some clay.

  It is not for actual use as a tool.  I have someone that wants a sculpture with no hammer marks or visible welds, grinding, etc.  It's all supossed to look "melted".  Think similar to Dali's melted clocks.  Sorry, I wasn't very clear. 

[NoGoodWithUsernames]

It should stretch no problem, the main issue I see is how you are going to do the stretching? I don't think you'll be able to just yank on it with one end held in a vise. I think you'll need more force than that, maybe one end in the vise and a come-along on the other end?

[Daswulf]

It could do some weird stuff in trying to stretch it. Plus you would have to have a strong mechanism to clamp and pull. I think actually trying to stretch them would be more trouble than it is worth. 

You could cut it and weld in a section. 

The key word is "visable" marks. If you are good with the finish work no one would be the wiser. Might take various flap discs, sand paper and maybe even soda blasted after but it can be done. Blemishes could be lightly hammered in to match the rest of the wrench. If forging just take extra care in your finish hammer work. 

I like the concept idea of the Dali melted clock. Not sure what the actual idea is with the wrenches but I like it already. 

[Glenn]

Stretching would depend on even heat across the entire length of the material being stretched. 

Clamping one end in a vise and pulling with a come-along would most likely bring the vise closer to the come-along before it stretched the wrench.  

You could use hydraulics to push the two ends apart.

[The Jeff]

Not sure how you would attach it, but maybe stretch if with a floor jack?

[JHCC]

What Daswulf said. I'd recommend replacing the handle entirely, as it will be easier to hide the welds in the transitions to the ends.

[Scott NC]

  Some good ideas and thoughts.   NoGoodWithUsernames, that's kind of what my idea was only I was going to string a comalong between two trees and use clamps.  Carefully.

  Aric, I may have a talk with him about making them forged or fabricated, I have faith in my skills.  It is a wall hanger with melted tools and pieces of melted tools dripping down the wall of his shop.  He's a retired mechanic.  If he likes it he said something more to stand outside his shop door.....

  Thanks Glenn, if I go the stretchy route, now.

  Jeff, I like thinking outside the box and file that away for future use.  

  Thanks John, I'll see what he says.  Now that I think about it the wrench ends might look funny as is, intact.  Maybe those could be "drooped" if gotten hot enough.  I really need to talk to him.  Thanks for ideas.

[Goods]

You will probably not have any luck stretching the wrench, hot or cold. Even the smallest difference in cross section or temperature, or material defect will cause that section to thin more. Once that starts, it’s all over… If you’re not wanting to add material, I’d make a spring swage with a similar, but much smaller cross section and use that to forge the length out.

Also, I guessing that the steel will burn before it hot enough to droop. (Maybe heat it hanging in an induction coil in a chamber filled with argon? I would love to see that! If I only had unlimited funds..)

Keep it fun,

David

[Latticino]

If metal is heated to the correct temperature, and held at that temperature while stretching, it is certainly possible to stretch it.  After all, that is essentially what we do on one side of a piece of stock when we bend it.  However it is no minor thing to maintain that even temperature or to safely provide the required force to do the stretching.  If I had to do this I would more likely do the fabrication that others have mentioned, but if the only choice was to actually stretch it, and the client had VERY deep pockets, I would be looking at coordinating with someone who had a extremely large tensile test machine.  I visited one recently owned by the Department of Transportation in Albany NY.  It was around 25' tall and could exert many tons of force.

[Scott NC]

   Thank you both, this is why I asked.  I like the swage idea David but there are several different wrench sizes he wants.  I thought this would be relatively easy.....  He will have to be satisfied with forged or fabricated.  I still want to find a way to make the wrench ends look like they are melting.  There is no deadline so I will experiment.  

[Scott NC]

1 hour ago, Latticino said:

It was around 25' tall and could exert many tons of force.

  Do you know what the material capacity of it was?  Did you get to see a test?  Great opportunity.  

[Latticino]

No, they had just finished a test when we were surveying the building.  We had been instructed to not talk to the techs, so I didn't get to quiz them, but clearly it had some power under the hood.  Looked like you could put whole truck frames inside and pull or crush test them.

[Daswulf]

I have a feeling they wouldn't want you heating the metal with torches while in their very expensive testing machine. 

Very careful forging might get you what you are looking for aside from fabrication. Probably a combination of both. 

 

You know what Does melt and deform more nicely without just burning ,like carbon steel, is aluminum. Any places that could cast you some replicas of the tools in the sizes you want to use in aluminum? Just an idea. Be even better for a wall hanger. 

 

[Scott NC]

  Unfortunately not that I know of and I have sworn off casting or I would try something along that line myself because it would be easier to achieve the look.  I'll just forge one out carefully like you suggested and see what I can come up with.  And fabricate if that goes bust.  Last resort, a combination of both.   I might try to stretch out a really small wrench (not discounting all the good advise here at all, just to satisfy my curiosity).  Even if it comes out all screwy, I could tie it in a knot and set it on the bookshelf....

[anvil]

I don't think you could stretch it without having a HUGE amount of power. Prolly not economically viable in most home setups.  That goes for heating it with a rosebud as well. 

You want to draw it out to a 2' length? That certainly fits the definition of a "long drawn out" experience. Do a quick and dirty calculation of the mass(weight per cu inch)o of the part you want to draw out, and then figure out a comparable thickness of material that is 2' long. Pretty slim pickins when done. 

You could always improve your hammer control and draw it out with no hammer marks.   or use closed die forging to not have hammer marks.

As for a melted look, thats tough as well. I believe you would have to heat it in an ox free environment or it will burn before it starts to melt. 

Dang, I hate being so negative,,, 

But, most important ---- have fun! 

[Scott NC]

  Yeah, that stretching idea is pretty much kaput.  I am still confident I can get a melted look just not what I originally had in mind.  "drippy" would be great and I have some ideas for that as well....   

  BTW that's not negative, just realistic.    And I am always having fun!  Well... usually.

[Frosty]

Oh I don't know, you're only doubling the length which would quarter the cross section. I'd take a lash at if the patron bought the gear. That first Dali-esk sculpture would cost thousands just for the stretched wrench. 

Clamping the wrench heads is easy enough, I've made a sketch of the cam clamp but it's taking forever to send/arrive so I can edit and upload it here. After that all you need is a goodly hydraulic ram with more than 12" travel. Porta power type pumps are available that develop in excess of 10,000psi. put that to a 6" ram will apply about 300,000lbs pull. Plenty.

Even heat is no problem for an induction heater. A coil of copper tubing around the wrench shaft could easily be connected to the clamps so it stretched with the wrench. A constant precisely controlled even heat is EZ PZ.

It'd have to be a vertical stretcher or gravity would sag the wrench. 

Once you have the equipment there's a world of cool things you could make with stretched, bent, twisted. . . ? tools. Open end wrench furniture anyone?

The state materials lab I worked in had a smaller version of a test press like that. Breaking concrete test cylinders wasn't even interesting. Breaking bar on the other hand had to be done after ours or people thought a bomb had gone off. 

Frosty The Lucky.

 

[Frosty]

Please forgive the lousy sketch but hopefully it shows how the thing works well enough. Nothing to scale but it's on graph paper! 

Frosty The Lucky.

 

[Scott NC]

  I admire your problem solving skills....  I don't doubt you could find a solution for any halfbaked scheme I come up with.  . Unfortunately, nobodys buying me any tools in the near future and induction heating is out of my wheelhouse, for now.  I was going to try using a pair of plate lifting clamps I have, but they have teeth that would mark the work, and a chain I would have to cut, ruining them.  I like your cam clamps and may make a pair for "experimentation purposes".  Thanks for the sketch.

  Now I'm having visions of stretched, melting pipe wrenches, sagging claw hammers, warped cresent wrenches, etc....

Edited April 9, 2023 by Scott NC
Change a thing

[Frosty]

Just explain to the commissioner what's required to make what he wants. Of course you're happy to make . . . IT for him but it requires the equipment. 

Make  a smooth jaw version of the plate clamps they work on the same principle, the harder you pull the tighter they get. Once you get eccentrics / cams in your head the potentials never stop. I'd planned on making an upsetting vise. Two shortish sections of heavy angle iron spaced a couple inches apart and sets of eccentric "jaws". A lever on one of the pivots to open the jaws both to receive stock or release it afterwards. 

The stand is what's convenient for you so long as you can hammer on it. I liked something open rather than a large piece of pipe, I like the idea of inserting and removing stock from underneath.

A claw hammer with a face smooshed on a giant nail would be cool. A large pipe wrench bent in a C around a piece of tiny pipe smiles to me.

Frosty The Lucky.

[Scott NC]

  I'm not used to selling things I make, let alone working the price of new tools into it.   My dad was salesman/businessman, he could probably sell even you something you didn't want, but I lack that gene or trait.  My whole family has it but not me....  I will try it though, can I give him your phone number so you can explain I'm not crazy, as in induction heater, porta power (we used those to compress railcar draft gears, and I have a story about that) and sundry items?  As far as streching wrenches goes I think I will start small and work my way up.....

 

[Frosty]

Sure, give him my number, I'd be happy to explain why he wants your kind of crazy working on his projects and why you need to equipment to pull them off. EZ PZ.

Let me know if you need help with that monster wrench. I'd suggest you start with TWO pieces of charcoal for heat.

Tried Totchos yet?

Frosty The Lucky.

[Scott NC]

  Tonight!