cutting torch

Just about where the points of the inner blue cones on the pre-heat flames are - that's the hottest part of the flame. Helps if the torch is properly adjusted (preheat flames neutral with cutting oxygen on)

For Oxy/Acetylene, about 1/2" from the tips of the inner cones to the metal.

With LP fuel gasses, like Propane, Propylene, MAPP, Chemtane, Flamal, or Natural Gas, the distance increases to 3/4" to 1-1/2" depending on which gas.

If you have the cutting tip too close to the steel you will tend to overheat the top edge of the cut causing rounded edges.

"Ernie Leimkuhler" wrote: (clip) If you have the cutting tip too close to the steel you will tend to

^^^^^^^^^^^^^^^^^ So it would be logical to start the process with the tip held closer to the work, to speed up the heating, and then draw it away as the metal comes up to proper cutting conditions. Am I right?

With Acetylene, the hottest point is just in front of the inner cones. With LP gasses, the hottest point is much further away.

Acetylene is is often too hot for clean flame cutting. The LP gasses are over-all not as hot as acetylene, but they are easily hot enough, and give a much cleaner cut for less money, and with a much denser fuel supply.