Which method allows for joining metal pieces using both heat and a filler metal?

Welding is a method that joins metal pieces by melting the base materials together, typically using a heat source such as an arc, gas flame, or laser. In most welding processes, a filler metal is often added to facilitate the joining of the metals and to create a strong bond between the pieces as they cool and solidify.

This process can be applied to various types of metals and allows for the creation of continuous joints, which usually have strength characteristics similar to or even surpassing those of the base metals. The application of heat not only melts the filler material but can also lead to a local melting of the base metals, ensuring a thorough mixing and fusion that results in a robust joint.

While other methods such as soldering and brazing do use heat and filler metals to join metals, they operate at lower temperatures compared to welding and involve different approaches in terms of melting the base metal. Mechanical fastening, on the other hand, does not involve any melting of metals but instead uses physical means to secure two pieces together. Therefore, welding is the appropriate method to identify when discussing joining metals with heat and filler metal.