Definition
An electric arc welding setup, also called direct current electrode negative (DCEN), in which the electrode is connected to the negative terminal of the power source and the workpiece is connected to the positive terminal. Electrons flow from the electrode to the work, producing shallower penetration and faster electrode melt-off compared with reverse polarity.
Plain English
A way of wiring up a welder so the electrode is the negative side and the metal being welded is the positive side. This makes the heat concentrate more on the electrode than on the workpiece.
Context Anchor
Seen in aircraft maintenance welding procedures and welding equipment setup instructions.
Derivation
Polarity' comes from the Greek 'polos', meaning axis or end — referring to the two opposite terminals of a circuit. 'Straight' here is a historical convention: early welders called the negative-electrode arrangement the 'normal' or 'straight' setup, and the opposite arrangement 'reverse'.
Why Pilots Care
Choosing the wrong polarity for the job produces poor weld quality — bad penetration, excessive spatter, or a weak joint. On airframe structures, weld integrity is a flight safety issue, so the technician must match polarity to the electrode and base metal.
Analogy
It is like connecting a battery-powered device the required way: one lead goes to negative and the other goes to positive. In straight polarity welding, the electrode is the negative side.
Intuition Check
Straight does not mean the weld bead is physically straight. Here it means the electrode is connected negative and the workpiece is connected positive.
Example Sentence 1
The technician set the machine to straight polarity welding before running a bead on the steel tube cluster.
Example Sentence 2
Straight polarity welding was chosen for the thicker landing gear component because it concentrates heat where needed most.