Random orbital sanders come in 5-inch and 6-inch pad sizes. The size affects sanding speed, maneuverability, and the surface area you can cover efficiently. Understanding these differences helps you choose the right sander for your typical workload.
Coverage Area
A 5-inch pad covers approximately 20 square inches of surface area per pass. When working a 24×48 inch table top, you’re making roughly 58 passes to cover the entire surface with some overlap.
A 6-inch pad covers approximately 28 square inches—40% more than the 5-inch pad. The same table top requires only 41 passes with the larger pad. This difference becomes significant when sanding large surfaces like table tops, cabinet sides, or door panels.
Sanding Speed
The larger contact area of a 6-inch sander removes material faster than a 5-inch sander, assuming equal orbit size and motor power. On flat surfaces over 300 square inches, the 6-inch sander typically completes the job 25-30% faster than a 5-inch model.
For small surfaces under 100 square inches—drawer fronts, small boxes, narrow boards—the speed advantage disappears. The extra pad size doesn’t help when the workpiece is smaller than the pad.
Maneuverability Differences
A 5-inch sander is noticeably more nimble in tight spaces and around corners. The smaller pad makes it easier to sand inside cabinet openings, get close to edges without oversanding, and work on furniture with detailed shaping.
The 6-inch sander feels bulkier and less precise in confined areas. The larger pad hangs over edges more readily, causing accidental rounding of sharp corners. For detail work and smaller projects, the 5-inch sander provides better control.
Weight Consideration
Five-inch sanders typically weigh 3.5-5.5 pounds depending on model and power. This lighter weight reduces fatigue during extended sanding sessions and makes the tool easier to handle with one hand.
Six-inch sanders weigh 5-7 pounds—roughly 1-2 pounds more than 5-inch models. The extra weight comes from the larger pad, housing, and typically more powerful motor. During all-day sanding sessions, this weight difference becomes noticeable in arm and shoulder fatigue.
Sandpaper Cost
Five-inch sanding discs cost approximately $0.50-1.00 each for quality hook-and-loop discs in bulk packs. Premium discs reach $1.50-2.00 each. The smaller diameter requires less abrasive material and backing, keeping costs moderate.
Six-inch discs run $0.75-1.50 each in bulk, with premium discs reaching $2.00-3.00. The larger size increases material costs approximately 40-50%. When you’re sanding extensively and changing discs frequently, this cost difference accumulates.
Dust Collection
Both pad sizes offer similar dust collection efficiency when properly connected to a vacuum. The dust collection effectiveness depends more on the dust port design and vacuum power than on pad size.
However, the 6-inch pad generates more dust per unit time due to its faster material removal. You’ll need to empty your vacuum canister or bag more frequently when using the larger sander on big projects.
Edge Work
Sanding narrow boards and edges is easier with a 5-inch pad. A board 4-5 inches wide accommodates the 5-inch sander without the pad hanging over both edges significantly. This reduces the tendency to round edges unintentionally.
The 6-inch sander is awkward on narrow stock. When sanding a 4-inch board with a 6-inch pad, you’re constantly managing pad overhang. The sander wants to tip, and you’re likely to round edges unless you’re careful. For projects with lots of narrow components, the 5-inch sander is more practical.
Motor Power
Five-inch sanders typically use 2.5-3.5 amp motors—adequate for the pad size and typical applications. The motor provides sufficient power without excessive weight or cost.
Six-inch sanders often feature 4-6 amp motors to handle the larger pad and maintain speed under the increased load. The more powerful motor adds cost but provides the torque needed to keep the larger pad moving through heavy sanding.
Orbit Size
Both pad sizes come with various orbit sizes—typically 3/32 inch or 3/16 inch are common. The orbit size affects how aggressively the sander cuts and the fineness of the scratch pattern.
A 3/32-inch orbit produces finer scratches suitable for finish sanding. A 3/16-inch orbit removes material faster but leaves slightly coarser scratches. This orbit size choice exists independently of the pad size—you can find both orbit sizes on both 5-inch and 6-inch sanders.
Application Guidelines
Choose a 5-inch sander for:
- Furniture building with varied component sizes
- Projects requiring detailed sanding and tight access
- When working primarily with smaller workpieces
- Situations where lighter weight reduces fatigue
- Users with smaller hands or less arm strength
Choose a 6-inch sander for:
- Large flat surfaces like table tops and panels
- Cabinet construction with lots of large components
- Production work where speed matters
- Flooring and deck sanding
- When you rarely sand small or detailed work
Combination Approach
Professional shops often own both sizes—using the 6-inch sander for large surfaces and rough sanding, and the 5-inch sander for detail work and smaller components. This approach optimizes tool selection for each task.
For home woodshops on a budget, the 5-inch sander is the more versatile choice. It handles large surfaces reasonably well while excelling at smaller work. A 6-inch sander as the only random orbital sander becomes limiting on furniture and detail work.
Used with Hand Sanding
Neither sander size eliminates hand sanding entirely. You’ll still need to hand sand inside corners, profiles, and areas the machine can’t reach. The 5-inch sander reduces the hand sanding area by getting closer to details. The 6-inch sander leaves more hand work but powers through open areas faster.
Calculate your typical work pattern: if 70% of your sanding is large flat surfaces, the 6-inch sander makes sense. If your work involves more varied surfaces and sizes, the 5-inch sander’s versatility outweighs the speed advantage of the larger pad.
