Bending Cast Iron - Can it be done?

[rmaynard 15,417]

I have a slot hitch that has holes that don't line up. 

 

 

When I removed the hitch, the pin would not budge in the hitch arms, but would rotate in the transmission. So I had to cut the pin on both sides between the transmission and the hitch arms. The long piece in the transmission came out easily, but the two pieces in the hitch had to be driven out.

 

So assuming that the hitch got bent while installed on the tractor, can it be bent back without breaking?

 

 

[Uncle Buck 246]

You can if you put enough heat to it, but that is going to be a WHOLE LOTTA HEAT!

 

Don't even think about it cold, that ain't gonna happen, it will snap like a twig. Maybe you could re-bore it instead?

[546cowboy 301]

The simple answer is NO! What you can do is run a drill bit though and try to line up the holes so you can put what looks lie a 3/4" bar through easily. That is what it looks like in your picture. A bit that size is not cheap but you may be able to borrow one from a hardware store or auto parts.

 

The only way you could try to bend it would be by heating it with a acetylene torch and if you use too much heat the cast can crystalize and break easily.   

Edited June 11, 2014 by 546cowboy

[buckrancher 2,679]

you can bend it back without heating I have done it many times the arms bent when you drove the pin pieces out

work from both sides back and forth does not take much of a tweek to line the holes back up

 

Brian

Edited June 11, 2014 by buckrancher

[tarcoleo 119]

Risky business trying to bend cast iron, hot or cold.   Suggest you ream the two holes simultaneously with a long reamer to

obtain proper alignment of both holes. It should not need a whole lot of reaming, but it might require that you fit a slightly

larger diameter pin.  Re reamers-

 

http://www.harborfreight.com/11-piece-adjustable-hand-reamer-set-38577.html

Edited June 11, 2014 by tarcoleo

[buckrancher 2,679]

this is cast steel not Iron there's a big differance

[rmaynard 15,417]

Thanks all. I do have a spare just in case it does decide to break instead of bend. I will follow up with results tomorrow.

[daveoman1966 3,745]

I have straightened many of these slot hitches.  Make it red hot with acetelyne and allow to air dry....otherwise it may become brittle. 

[Tankman 3,518]

By all means, use a reamer. You might ask a local machine shop to ream it for you.

 

The cost would be low and of course worth the effort.

[rmaynard 15,417]

daveoman1966 - I don't have a torch, so heat is not an option at this time.

Tankman - taking it to a shop would cost more than buying another good used one. Machine shops around here are not cheap.

As I said, I have a spare, so I am going to try tweaking it.

Sent from my Moto G using Tapatalk

[Kelly 1,029]

I've fixed many of them, I use heat, and a old steering shaft to put it where I want. then when the shaft slides in both sides I'm done.

[dclarke 4,032]

I've tweaked 'em before with a big brass hammer and a vice. Maybe I got lucky.

[buckrancher 2,679]

Bob if you put the pin in and check the gap at the other side be sure to check it from both sides all you may need to do is squeeze  it a little in a vise and the holes should line up

 

brian

[Coadster32 793]

Hey Bob, if you know somebody with a press, this can easily be done. You really don't need much movement to get it re-aligned. Even if not perfect, you could turn one end down to get it to go in. I agree with Brian, it was aligned once before, and got bent. No real reason why you can't bend it back.  

[Brrly1 1,146]

Bob, a real easy Super solution has evolved. Use the other one, I'll bet this is for a tractor your bringing to the show so I would really  expect the paint to be dry and it'll be on or in your trailer when we see you next Thursday. 

[rmaynard 15,417]

Okay, so after all the input and suggestions, I have chosen Brian's suggestion to give the hitch a few strategic raps with the hammer and...

 

 

Voilà

 

 

...it can be done. And with minimal paint damage as well.

 

Thanks!

 

[tarcoleo 119]

Hurrah!!!

[buckrancher 2,679]

[Brrly1 1,146]

See you in eight days! Don't shoot the sawman!

[jdleach 525]

Yup, probably cast steel. The cross sectional area of the arms is really too small to be cast iron, and the slot pretty much rules a forging out. Steel.

Cast steel, in fact any cast metal, tends to be brittle. The rolling process in a steel mill tends to align the molecules, and impart toughness.

That said, cast steel, stainless, brass and bronze, etc, will more readily bend, hot or cold, than cast iron, you just don't want to bend it very far.

When looking at a part that appears to be cast, there are a few easy tests that anyone can do to determine just what the part is. If magnetic, it is ferrous-based, and either iron, or any number of steels or stainless (your lower grades of stainless are indeed often cast, and will be magnetic). A forging will many times visually resemble a casting, but will almost always be steel. Also, forged shapes tend to be simple, think U-joints, wrenches, hammer heads, tie-rod ends, etc.

If you have determined the part to be a ferrous casting, grind a little off with a sander, bench grinder, etc., and look closely at the spark pattern. Steel will emit a copious shower of bright yellow sparks. If cast iron, the sparks will be much more muted, shorter in length, and duller. The difference is easily discernable.

[tarcoleo 119]

See entry below.

Edited June 13, 2014 by tarcoleo

[swarfeater 49]

cast iron would never be used for this application, it would break with the first good load put on it,  a smack with a hammer will do the trick.

[tarcoleo 119]

http://en.wikipedia.org/wiki/Cast_iron

 

In this article there is a table showing the properties of various grades of

cast iron.  The elongation properties of the malleable and ductile grades

suggest that one of these is the material used for the slot hitch.  Its not

likely that the grey or white grades of cast iron were used.

 

(Tried to print the table above earler but it didn 't come out right.)

Edited June 13, 2014 by tarcoleo

[jdleach 525]

Should have mentioned ductile and malleable tarcoleo, that would work in this application too. You used to often find malleable in things like "C" clamps.

 

Good call.

[tarcoleo 119]

Not to beat this topic into the ground, but "steel castings" tend to

involve highly alloyed steel in order to obtain increased heat or

corrosion resistance.

Edited June 13, 2014 by tarcoleo