What is a DA sander used for?
Regarding this, what is a DA sander?
Before I start on the reviews, you should know that a DA sander is a random orbital sander. A dual action sander has two actions: one with the spindle (of the motor) locked to the pad, the other isn't locked but has a bearing between the spindle and the pad.
Subsequently, question is, how does a orbital sander work? Orbital sanders work by elliptically rotating a sanding disk. No matter the wood grain's direction, an orbital sander will smooth the surface without leaving marks. Because of this, you can easily sand two pieces of wood at the same time, even if their grains are in different directions.
Then, is a orbital sander the same as a DA sander?
Random orbital is a dual action (DA) sander. Different companies, different names, both the same.
Why is an orbital sander called a DA?
Back to the basics -- A dual action (DA) sander is called "dual action" because it can be run in two separate and distinct modes. One mode is orbital (when the air motor spindle is locked to the sanding pad).