Complex sentence: Percussion welding is similar to flash welding and upset welding but is generally considered to be more complex because it uses an electric discharge at the joint, followed by pressure being applied to join the materials together.
Split into simpler sentences: Percussion welding is similar to flash welding and upset welding but is generally considered to be more complex. It is considered to be more complex because it uses an electric discharge at the joint, followed by pressure being applied to join the materials together.