5" vs 6" Sander: Which One Do You Need?
AUG 20, 2026
The short, simple answer to which random-orbital sander size actually fits your shop — and why most woodworkers end up owning both eventually.
THE SHORT ANSWER
Building small stuff — boxes, frames, trim, edges? Get a 5". Leveling tabletops, cabinet doors, or big flat panels? Get a 6". Most woodworkers start with a 5" because it's more versatile, then add a 6" once they're regularly working on bigger pieces.
What actually changes between the two
The disc size changes more than just the number stamped on the sander. It changes how much surface you cover per pass, how heavy the tool feels after an hour, and which dust-port pattern your discs need to match.
| What changes | 5" (125mm) | 6" (150mm) |
|---|---|---|
| Sanding surface area | ~19.6 sq in | ~28.3 sq in — about 44% more |
| Feel in the hand | Lighter, easier one-handed control | Heavier, usually needs two hands on long runs |
| Best at | Detail work, edges, small parts | Covering large flat surfaces fast |
| Common hole patterns | 8-hole, 9-hole (Festool/Mirka) | 6-hole, 49-hole (multi-hole) |
| Tool & disc cost | Generally the cheaper option | Usually a bit more for both sander and discs |
Pros and cons
Weighed side by side, with nothing glossed over.
5"
125mm
Pros
- Light enough for long stretches of one-handed sanding
- Easiest size for edges, corners, and tight spots
- Cheaper sander and cheaper discs
- Most common size — widest disc and accessory selection
Cons
- Slower going on large, flat surfaces
- More passes needed to cover a tabletop or door
6"
150mm
Pros
- Covers roughly 44% more surface per pass
- Fewer passes on tabletops, doors, floors, and panels
- Better fit for production runs and bigger projects
Cons
- Heavier — more fatigue over a long session
- Bulkier, harder to control in corners and tight spots
- Slightly higher cost for sander and discs
How to decide, by project
If the quick answer above wasn't specific enough, here's the breakdown by what you actually build.
5"
Boxes, frames, trim, and jewelry. Small parts and tight corners favor the lighter, easier-to-control size every time.
6"
Tabletops, cabinet doors, and floors. The extra sanding area means fewer passes and less time standing over a single panel.
Both
General furniture making. If your projects vary in size, a 5" for detail work and a 6" for glue-ups and panels covers you either way.
5"
Only buying one, and projects are mixed. The 5" is the more versatile all-rounder and the easier sander to learn on.
Whichever size you land on, we've got the discs.
Purple Film and Green Disc are both stocked in 5" and 6", so switching sizes later doesn't mean switching abrasive lines.
