What color does the inner cone of an oxidizing flame appear?

The inner cone of an oxidizing flame appears blue. This is characterized by a higher presence of oxygen in the flame, which facilitates more complete combustion. As a result, the combustion reaction gives off a vivid blue color, indicative of efficient burning.

In welding and brazing processes, recognizing the color of the flame is crucial for achieving the correct heat profile and ensuring proper joint formation. The blue color indicates that the flame has an appropriate balance of fuel and oxygen for efficient heating.

While other flame colors can occur under different conditions, the blue of the inner cone in an oxidizing flame is a well-established guideline for professionals working with flames in metalworking contexts.