Technical Melting steel

The net says a standard propane torch can reach 3500f with ambient air. Why cant it melt steel then?

 

Even at that temperature, the flame loses too much of its heat to the surrounding air before it can transfer to the metal.

 

Silas, from the "Adventures Made From Scratch" YouTube channel, regularly uses propane on his cutting torches. This is a junkyard/car crushing channel and he claims that the oxygen/propane cuts a little slower, but the total cost is much cheaper than oxygen/acetylene.

Russ

 

I would also factor in the fact, depending on size and thickness, that the metal is also working at dissipating the heat at the same time.


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M*** versus available energy.

Standard soldering propane torches, were not designed to melt steel.

 

It depends if you are using compressed oxygen or air with the propane. Propane /air flame (19% oxygen) vs Propane/100% oxygen . I have been using propane/oxy to cut steel for many years, I have cut up to 1/2" plate with it.

 

less expensive too. Also need a different tip.

 

Oxy propane is pretty common in wrecking yards. I gave probably seen more oxy propane rigs than oxy acetylene in the last few years.
The guys say the reduced cost more than makes up for the slightly lower temperatures.

The little propane torches don’t flow enough propane to cut steel, and don’t have enough oxygen available without a bottle of compressed O2.

 

I worked in a shop that had aCNC torch table that used propane for fuel. It would cut 8" plate.

Gary

 

Propane works fine. Will cut as well as acetelyne. Just a tad slower, but was always less expensive. The top for propane looks like a 12 fluted looking thing.
It’s too hot out, or I’d go snag a pic.
I think my dad said it wouldn’t make a clean a cut, but my hands aren’t steady enough to tell a difference

 

Propane can build enough heat, it just needs a bit more oxygen to alter the form of the hot steel from the solid form to the liquid form. If the steel is thin enough, enough propane can indeed begin melting it.

 

Put the small torch in a well insulated forge of suitable size (i.e. very small), let it heat up the forge interior to the same temperature as the flame so the walls radiate heat at anything you put in there and you may very well reach melting temperature on very small steel items. You will, however, also reach the melting point of the torch, as it is designed to work in free air, cooled down instead of having huge amounts of heat radiated at it.