heat treating stock axles

The broken torsion bars from the Vals. made beaut chisels and punches. I had to soften them by heating dull red and leaving in a pot of lime overnight to make them machinable. Had to use tungsten carbide and with some difficulty. Then heated and oil quenched them after machining, forging, grinding. Leave the striking end soft for safety.

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Originally Posted by JDNSW

The angles quoted assume the material is isotropic with the same properties in all directions, I question whether this is exactly the case for axle shafts, especially for induction hardened ones, although I agree the stress angles will usually be close to 45 degrees in practice.

I encountered one interesting failure (in a rear axle on a 6x6 IH R190) - failed about four inches from the outer end, with a clean break that looked as if it had been cut with a parting tool. It was a replacement axle for one that had failed with the classic spiral break starting from the end of the spline, and failed the first time low range was used after it was fitted, when it sank a couple of inches in very slippery mud.

John

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Most I've seen are like that

https://www.aulro.com/afvb/images/im...12/01/1019.jpg

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Originally Posted by Slunnie

Most I've seen are like that

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Same here - every 24-spline axle or CV stub I have broken or seen broken has looked like it was cut with a drop saw.

By comparison, 10-spline series axles break in a much more jagged pattern.

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Originally Posted by isuzurover

Same here - every 24-spline axle or CV stub I have broken or seen broken has looked like it was cut with a drop saw.

By comparison, 10-spline series axles break in a much more jagged pattern.

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I wonder if you are seeing the difference between overload failure (ten spline) and failure due to fatigue initiated at a stress concentrator such as a material flaw or surface defect (24 spline or CV stub)?

John

Quote:

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Originally Posted by JDNSW

I wonder if you are seeing the difference between overload failure (ten spline) and failure due to fatigue initiated at a stress concentrator such as a material flaw or surface defect (24 spline or CV stub)?

John

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I doubt it. Most of the 10-spliners failed (finally) at low-load - e.g. on-road in high range or even when going downhill in one case!!! So these were most likely fatigue related...

Whereas some of the 24-splines failed at full noise...

However since Dave Ashcroft has shown that the UTS of 10-spline and 24-spline axles are about the same, I think the point is moot. I am sure the difference comes down to grain structure.