Cutting axle shafts with torch

Cutting plate, angle or other shapes is st a matter of running the torch at a constant speed, as the material is a constant thickness. Now look at a round. You have to move faster at the beginning, then slow as you approach the middle and then speed up again as you get out near the edge again. Keep that in mind, mainy the slowing down in the middle and things will go well.

Torch should blast through a typical axle with no problem.

What you say about using propane is true, but the way you say it makes it possible for someone to form the wrong idea about it. It's true that propane provides less heat than acetylene but the only effect this should have on cutting is to make heating the metal to the kindling temperature take longer. Once the actual cutting begins, the type of fuel gas being used is no longer a factor. T_Bone has written about, and I have seen, the fuel gas turned off while the cut was being made. The stream of pure oxygen burns the steel, which is the fuel once combustion begins so no fuel gas is needed. Of course, it takes quite a bit of skill to maintain a cut so most people couldn't finish with only the oxygen. If the cut is lost there is little time to start it again with only oxygen---once the steel cools below the kindling temperature, a stream of pure oxygen will serve as a cooling gas, like blowing on your coffee to cool it.

All the best, Stan

I'm not sure what you're saying here. If you're saying that a little bit of cutting on thin metal can be accomplished without any preheat whatsoever, I'll take your word for it. If you're saying that once cutting is under way it can only be maintained if the preheat fuel gas continues to be applied, I don't think that's correct. The heat of combustion is enough to continuously raise the metal immediately ahead of the cut to the kindling temperature or higher. For practical purposes it may be unlikely that a person cutting thick, cold metal by hand could keep the cut going, but it's technically possible. A track cutter, for instance, once it was cutting, could continue cutting even with the fuel gas turned off, regardless of the thickness or temperature of the metal.

All the best, Stan

Melting your way through something is what happens with some materials which can't be cut in the usual sense. Cast iron falls into this category, and stainless steel too, I think. Someone who cuts all the time at a scrapyard would have plenty of experience cutting solid cylindrical objects. What Joe says about using too small a cutting tip is probably the case if the axle shafts are just regular steel. Too small a cutting tip will fail to cut all the way through which causes the molten slag to blow back up out of the cut. It looks a lot like trying to cut cast iron but it's not the same. The metal is being cut, just not cleanly or completely. In that case, a bigger tip at the right pressure would do it.

All the best, Stan