Cut to length Cromo rear axles...

ghost

ghost

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Joined
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Hartsville/Camden,SC
So I'm pretty sure I broke a rear 35 spline D60 shaft this past weekend. I've had it in there for a few years now. It was a standard cut to length shaft I got from ECGS. I see ECGS has cromo cut to length.

https://eastcoastgearsupply.com/c-2...shafts-rear-dana-60-chromoly-axle-shafts.html

School me.... I thought cromo was a heat treat and that heat would weaken them? Or is Cromoly the mixture of material in the metal?
 
ghost said:
So I'm pretty sure I broke a rear 35 spline D60 shaft this past weekend. I've had it in there for a few years now. It was a standard cut to length shaft I got from ECGS. I see ECGS has cromo cut to length.

https://eastcoastgearsupply.com/c-2...shafts-rear-dana-60-chromoly-axle-shafts.html

School me.... I thought cromo was a heat treat and that heat would weaken them? Or is Cromoly the mixture of material in the metal?
Click to expand...
I have one from ecgs that had to be cut down. If you have access to a cold saw, heat wont be an issue. Cant really comment on the metalurgy aspect, though.
 
I'm pretty sure they'd be heat treated. Even if they are, you'd have to get them very hot to change the tempering. Not sure how you'd cut them though. Cut-off wheel and dress with a flap disc? :)

I'm sure the engineer types like @jeepinmatt or @Fabrik8 have an intelligent answer
 
I used a chop saw with an abrasive blade to cut mine down. De-burred the edges with a bench top grinder. No problems with mine in the last couple of years.
 
ghost said:
So I'm pretty sure I broke a rear 35 spline D60 shaft this past weekend. I've had it in there for a few years now. It was a standard cut to length shaft I got from ECGS. I see ECGS has cromo cut to length.

School me.... I thought cromo was a heat treat and that heat would weaken them? Or is Cromoly the mixture of material in the metal?
Click to expand...

Chromoly is a portmanteau of chromium and molybdenum which are some of the alloying elements of the most likely 4340 in the axle shafts, has nothing to do with the heat treat process. Most likely they are induction through hardened (vs case which leaves the core soft). All that really means to you is that your regular ol sawzall or bandsaw blade probably won't last too long cutting.
Abrasive saw will be fine, if it starts glowing orange you might be up into tempering temps.
 
You're not dealing with heat treated weld joints in 4340, and even if you cut it with a crappy abrasive blade that puts more heat in the base material, you're probably not going to heat it up far enough down the shaft to matter. Most bi-metal bandsaw blades are some type of cobalt (M42, etc) and probably will be able to cut through treated 4340 with mixed success. Without knowing the type and depth of heat treat, hardness of material, etc, I'd grab my portaband and waste an $8 blade trying to cut it. If that didn't work, I'd just cut it with an abrasive saw. If you're really worried about it, cut 1/4" quickly, let it cool, and repeat until you're all the way through. Best way is a carbide cutoff tool in a lathe, which I'd be happy to do for you if you were closer.
 
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R Q said:
Or you could just call Chase at ECGS and ask him...
Click to expand...
That was the plan. What they suggest to cut them down with. I might can find a cold saw. I know I can get a friend to use his lathe. I was just curious about the whole metal thing and trying to understand what the difference was. I know the pair I have in my 60 are not cromo. I never thought my 4.0 auto 203/205 would break a 35 spline shaft..... but then again they have been beat on for a few years. Thanks for the quick response and education.
 
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