Pictures of a broken cast I-beam axle

ballots, dry flys, stones..........

 

Here's a good list-
http://www.sorelmetal.com/en/publi/PDF/083_(2006).pdf

 

I knocked one of those cast axles off my work bench by accident and the thing broke in two when it hit the floor!


Ok that didn't really happen...

 

Lotsa is correct, as are many others here. Totally speculative to say 1 cast part is better/worse than a similar part that is forged. Too many factors to know for sure:

1. Metalurgical composition, what does the metal actually contain (carbon, etc.)?
2. Cast/forging process, what were the heating/cooling procedures?
3. Accident impact, can you identify what aspects (force, direction, etc.) caused the break?

Chemical alterations from plating is an excellent topic to cover and I for one would worry much more about that cast/forging. Many race teams learned these ill effects years ago when using suspension parts that were nickle plated vs painted (days prior to carbon fiber).

 

Not the 1st one that I have seen. Just be careful on what you buy. I can say that I have never seen a forged one snap.

 

What else can you think of that is cast?

A Shadow, A Spell, off, a movie, a way

 

the forging also relieves some of the stress on the metal that is caused in a casting process,remember a casting cooling cools at different rates and different parts of the casting, this causes stress to be built into the casting itself. the forging process relieves this stress as the part is formed. this is the same reason sword blades are forged not cast, at least the real ones. if a blade was cast,it would snap with any kind of impact. a forged one wont. A forged suspension part is much less likely to break then a cast one,it can flex to a degree with no damage. For my money I would trust the forged parts.

 

I guess some of you are missing the sales pitch.
Dave tried to scare me into buying an axle from him years ago.

http://www.roadsters.com/axles/

BTW, I just read through Dave's website again. It's really really fancy. Has anyone ever visited his shop???? I have...

 

Is the ford axle good and will it be good after it has been dropped ? They say never heat up suspension parts or they will fail . I think it is B.S to a certain point .

 

No worry about breakage,it's "seasoned"

 

I'll see your "tuna boat",and raise you a "land yacht".

I'd ride in your "tuna boat" anytime!

 

Scare you or educate you?
So what's up with his shop? BTW my motto is...it's not what you got, it's what you do with what you got... does he do more with less?

 

Lets see - this is 2008 (And late in the year)
Ford has been using this axle since the Model T
It was used in cars thru 1948
and on truck's on F-100 2x2's to 1964
Do we know how many have failed?
1 in a million? 2?
I think we got a little anal-cranial inversion going on here

 

The forging process does not relieve the stress induced by beating the metal into a new shape, however, the heat treatment the forging receives after it is forged does. When you heat and drop a forged axle, you actually induce new stresses and negate the properties imparted on the metal by the initial heat treatment. In all honesty, a dropped axle should probably be heat treated once again.

A casting of ductile iron goes through a heat treating process too, called spheroidizing which transforms the shape of the graphite present in the casting from flakes (which act as initiation points for cracks) to spheres (which act to stop cracks from propagating when they form).

If a properly designed part is properly manufactured, there will be no problem with it, regardless of whether or not it is cast or forged.

That is not to say that all castings are just as good as forgings, however, it also cannot be said that all castings are automatically inferior to forgings.

There is just too much data going into a design and the process that manufactures it to make that kind of sweeping judgement.

I do not think that I would cast aside (ha! pun ) all cast axles just because this one broke when it ran into a tractor/trailer rig.

It had an impact, its troubles are over. Even if it hadn't broke, I wouldn't run it again, not after a lick like that. Same thing with a forged axle. If it bends and has to be straightened, I'd not run it again until it had been stress relieved (or heat treated again if it had heat applied to straighten it) and magnafluxed or dye checked. In fact, I don't think I'd run an axle that had been dropped either until it had been heat treated again and magnafluxed or dye checked for cracks.

I have crappy luck, so I can't take any chances. If it can go wrong, it will go wrong, when it's attached to MY car. lol

 

Yes. Magnum axles have never “broken” or “snapped”. Magnum knows of one that’s almost folded in half because of an accident.

Not everyone can afford a real ’32 axle or the years it takes to find an affordable one.

 

Way back when ... Ford had a lot of people nervous about this "spindly" looking front axle.
(seems things haven't changed much ! )

So to demonstrate the strength of their FORGED front axles; they mounted one in a huge lathe. Holding one end in a clamp mounted on the bed way that didn't turn, and the other end in the chuck.

They wound that axle up like a "cork screw" - it's said they twisted it TWENTY TIMES - then they RE-INSTALLED it under a car and went touring around.

I've seen pictures of the axle being twisted in the lathe and under the car - and it was still "going strong" many years later.

 

Excellent post but wanted to make a small clarification. Ductile/nodular iron is made that way during the casting process by the addition of magnesium. It's added to molten grey iron (violent and pretty to watch) just before pouring then the casting solidifies with a nodular/spherical structure. There may be a normalizing heat treatment later on, but most castings get that and it's unrelated to the carbon structure.

 

What makes you assume he can educate me or you or anybody.

He doesn't have a shop, he's a middle man and obviously a marketing genious.

WHAT HAS HE DONE??

 

So, he makes money selling parts. Whats wrong with that?

 

Yes, they are inoculated with magnesium (or sometimes lead), but those catalysts really work their voodoo during the extended heat treat. The mag is the spheroidizing agent, but the process takes longer than the metal takes to freeze in the molds. The elevated temp of the heat treatment post casting lets the spheres finish forming. By changing the heat treatment, you can change the shape of the graphite nodules from near flake shaped to spherical and everything in between (and thusly give the material a whole host of different properties).

Ductile iron is a huge field with many thousands of alloys tailored to specific applications. That's why I say it's lunacy to declare that all cast parts are crap, 'cause given the near infinite variety of alloys and applications thereof, there's just no way to know by looking that the part is junk.

 

Nothing.

Go back and read the whole thread.

 

AhhhhHaaaaa! So the truth comes out! Dave has an ulterior motive for the scare tactics! Seems the Peehonix locals got a feel for him?

Really dave I have no beef with you. You did however step into my sights twice in the last couple weeks and made it pretty easy. But this thread just reeks of Yellow Journalism. Guess this means you wont sell me some Gibbs?

 

I had a person bring me a tube axle that came apart at the weld. Sure F<>Ked the car. No one got hurt just pride and the pocket book.

 

You can buy Gibbs straight from the source, get a frame from Kiwi connection and get an axle dropped at Chassis eng. all on your own.

 

Thanks but I am building my own frame and I have an original dropped axle. Plus my stuff will have paint like last time so the Gibbs thing was kinda a rhetorical question

 

So the debate is which model of the beefiest piece of the entire front end is stronger, a cast or forged axle, right?
Anyone giving any thought to the shear strength of the bolts that hold the spring to the car? The strength of the spindle itself? How about the wheel? I'm thinking if you hit a curb or pothole hard enough to snap a beefy axle, you're going to trash the wheel, the steering gear and probably the radius rods.
If you hit a curb hard enough to break an axle, you're certainly also at risk of breaking the mounting point of the radius rod, or any of the hardware that holds the whole thing together.

I broke a Craftsman screwdriver once by using it as a chisel...now I think every Craftsman screwdriver is junk.

-Brad

 

Exactly.

I don't see how anyone can say one piece of the system is weak or unsafe until they have run the numbers and seen for sure what is what.

My gut tells me that the weakest link in any of these front end systems is the single shear split wishbone mounts you always see. The hardware is always suspect as well, unless it's all replaced with fasteners of known strength (grade 5, grade 8, etc). But none of it can just be assumed to be wrong or dangerous (just like it ought not be assumed to NOT be dangerous) until you've run the numbers.

This stuff is all calculable and quantifiable. It's not black magic, it just takes a lot of math and a lot of time.

If something looks overkill, most likely it is, but running the numbers will tell you for sure. If something looks marginal, do a stress check and see if it needs to be changed.

Putting a tiny ass forged axle under a 6,000 LB car without doing a stress check is just as stupid as putting a tiny ass cast axle under that same car without doing a stress check.

By and large, instead of the part itself simply being inferior, I believe that part failure is generally attributable to poor engineering (or rather the misapplication of a properly engineered part) on the part of the constructor. Sometimes bad QC will send parts out the door that won't function or live under any circumstances, but like I said, those seem to be the exception, not the rule.

As always, I could be entirely FOS, I'm just an engineer who likes old cars.

 

Great minds think alike

 

Well, at least three of us had this thread figured out...

Brian

 

No big deal, it hit something hard and it will either break or bend.
If it bends or breaks your vehicle is still screwed as far as control goes.
Cast usually breaks and forged usually bends.
Your buddy needs to take a good look at himself as drunk driving gives hot rodding a bad name and involved in an accident to boot.