Random Orbit
Affiliate link — we may earn a commissionRandom orbit means the sanding pad spins and orbits simultaneously in an irregular pattern. The pad rotates on its center axis while also moving in small elliptical loops. This combination prevents the sanding scratches from forming a visible pattern. A sheet sander or belt sander leaves directional scratch marks that show through stain. A random-orbit sander leaves a scratch pattern that's effectively invisible to the eye. That's why it's the default sander for finish work on furniture, cabinets, and trim.
Why It Matters
If you're staining or applying a clear finish, directional sanding marks ruin the result. Random orbit eliminates visible scratch patterns without you having to think about grain direction. It's slower than a belt sander for stock removal, but the surface quality isn't comparable.