The approximate temperature of an oxygen-acetylene torch at the tip is usually significantly higher than that of an air-acetylene torch. As a result, oxygen-acetylene torches heat the base metal faster than air-acetylene torches. Air-acetylene torches have a larger and broader flame, and oxy-acetylene flames tend to be more concentrated and precise. However, when using an air-acetylene torch, you must be careful because they give off more convective heat, which can damage surrounding components in the work area or cause injury. You may need a heat-blocking substance like the Refrigeration Technologies WetRag HeatShield.

In general, it takes a bit longer to set up an oxygen-acetylene torch with the proper amount of oxygen and acetylene because you have to set that ratio manually. You also need to use a striker to light an oxygen-acetylene torch. Air-acetylene torches achieve the proper ratio automatically, as they draw in air and mix it with the acetylene gas. Many of these also have a sparking mechanism built into the handle.

Overall, air-acetylene is less likely to burn through the tubing but more likely to cause heat damage to surrounding components. It cannot weld steel, but oxy-acetylene torches can. They have more of a wrap-around flame and tend to be less expensive than oxygen-acetylene torches, and they’re often lighter because they leave you with fewer cylinders to carry (and without a pressurized oxygen tank, which can be dangerous).

Overall, air-acetylene torches are best for newer technicians, and oxygen-acetylene torches work better in the hands of experienced techs in tight, concentrated areas.