Category: Sanding & Finishing

Which grit for which job: wood, paint, metal

The grit number tells you how coarse the abrasive is: the lower the number, the bigger the grains and the harder it cuts; the higher the number, the finer the grains and the smoother the surface it leaves. Here are the ranges you’ll reach for most often in the shop. More sanding guides live in our Sanding & Finishing section.

The rule that saves you from bad surprises: always work from the coarsest grit you need to the finest, never the other way around, and don’t skip more than one step at a time (80, 120, 180, not 80 then 180), or the scratches from the previous grit will show through the finish. And hook your sander to a vacuum: our best shop vac guide explains which filter actually catches fine sanding dust.

The “P” trap: CAMI vs. FEPA grits

A “400” isn’t always the same 400. Two grading scales share the shelves in the US: the American CAMI scale (also called ANSI), which shows only the number (400), and the European FEPA scale, recognizable by the “P” in front of the number (P400). Many assortments sold on Amazon.com are made overseas and graded on the P scale. From 40 to 220 grit, the two scales give almost identical particle sizes.

Values from Klingspor’s coated abrasives grit chart, checked October 27, 2026. One micron is 0.00004 inch.

Two assortments that cover most jobs

Rather than buying one pack per grit, a mixed assortment means you never run out halfway through a project. We checked availability, ratings and prices on Amazon.com on October 27, 2026.

For a random orbit sander (5-inch hook-and-loop discs, 8 holes): the POTUINOM 165-piece assortment covers 40, 60, 80, 120, 150, 240, 320, 400 and 600 grit, 20 discs of each plus 5 extra 40-grit discs for stripping. That’s everything from rough removal to the final pass before finish, without a mid-project trip to the hardware store. $19.99 (checked October 27, 2026), rated 4.7/5 from 2,726 ratings, in stock. Check the price on Amazon.

For an orbital (1/4-sheet) palm sander or hand sanding (4-1/2 × 5-1/2 in. sheets): the Milescraft 1623 50-pack covers 80, 120, 150, 220 and 320 grit, and works wet or dry. $13.47 (checked October 27, 2026), rated 4.6/5 from 1,885 ratings, in stock. Check the price on Amazon.

Not sure which sander you need? Our orbital vs. random orbit sander guide explains what each one does best, and our Black Friday 2026 power tool deals page lists the sander prices to beat this fall.

How we choose: never a single grit, always an assortment that covers at least three steps. For something as disposable as sandpaper, availability and a rating checked on the day count for more than a famous brand name.

When an assortment isn’t the right buy

• You’re only sanding drywall patches: a couple of 120 to 150-grit sanding sponges will do the job with less dust.
• You’re wet-sanding a car’s clear coat: you need silicon carbide wet/dry sheets from 1,000 grit up, not a woodworking assortment.

FAQ

What does the grit number on sandpaper mean?

It’s a measure of coarseness: the higher the number, the smaller the abrasive particles. On the FEPA “P” scale, P40 has particles of about 0.016 inch (412 microns) for stripping, P120 about 0.005 inch (127 microns) for prepping wood, and P240 about 0.0023 inch (58.5 microns) for sanding between coats.

What grit sandpaper should I use on bare wood?

Start with 60 to 100 grit to flatten rough lumber or remove a flaw, then finish with 120 to 180 grit before stain, paint or a clear finish.

What grit should I use between coats of paint or polyurethane?

A fine grit, between 220 and 400, is enough to lightly scuff the surface between coats without cutting through the finish.

Why doesn’t every “400 grit” sheet feel the same?

Because two scales coexist: the American CAMI scale (marked 400, no P) and the European FEPA scale (marked P400). Above 220 grit they diverge: a P400 is about as coarse as a CAMI 320, while a CAMI 400 is about as fine as a P800.

Do random orbit and orbital sanders use different sandpaper?

Yes, the format changes: round 5-inch hook-and-loop discs, usually with 8 holes, for a random orbit sander, and rectangular quarter sheets (4-1/2 × 5-1/2 in.) for an orbital palm sander. The grit you choose follows the same rules on both.

Our verdict

Our pick: the POTUINOM 165-disc assortment at $19.99, rated 4.7/5 from 2,726 ratings (checked October 27, 2026). Nine grits from 40 to 600 for less than the cost of redoing one finish, and you’ll never stall a project for lack of the right disc. Sanding by hand or with a palm sander? Add the Milescraft 1623 quarter-sheet pack at $13.47. Sandpaper is the most underrated consumable in the shop: keep at least two grits ahead in the drawer and your finishes will thank you.

Get the POTUINOM 165-disc assortment on Amazon →

See all our picks on our recommended tools page.

🗓️ Prices checked on October 27, 2026. They move often: check them again before you buy.

Written by Julien · Reviewed by Nadia on 10/27/2026 (prices, links and availability checked) — our editorial pen names

Orbital sander or random orbit sander: it’s the first question anyone setting up a shop asks, and the answer is less about brand or power than about the shape of the pad. This guide is part of our Sanding & Finishing section.

Four sanders to settle the question

These four are popular, well-reviewed picks on Amazon.com in each family. We put them side by side to help you pick a family, not to crown a brand: prices, ratings and rating counts were checked on Amazon.com on October 27, 2026.

What actually matters when you choose

What’s the difference between an orbital sander and a random orbit sander?

It comes down to the motion and the pad. A random orbit sander spins a round 5-inch pad while moving it in small ellipses: it removes a lot of material quickly without leaving a pattern on large surfaces. An orbital (or “sheet”) sander shakes a square pad in tiny circles: slower, but it reaches into corners and gives a fine finish.

The shape of the pad, and nothing else

That’s the whole question. The random orbit’s round pad spins and oscillates at the same time, so no two passes trace the same path and you don’t get repeated scratch marks. The orbital’s square pad vibrates in place: it gets into corners, edges and tight spots, but it leaves more visible swirls if you bear down. Power, brand and price all come after this difference.

The random orbit removes, the orbital finishes

At the same grit, a random orbit sander takes off far more material and works much faster on a big flat surface: a tabletop, a door, a countertop. An orbital sander is gentler and slower, made for scuff-sanding before paint and for small surfaces. Stripping an old finish off a dining table, the time difference is counted in hours. Pick the right paper too: our sandpaper grit guide tells you where to start and where to stop.

What a random orbit sander will never do

It can’t get into an inside corner. The round pad stops a fraction of an inch short, and forcing it against the wall chews up both the pad and the workpiece. It’s the family’s only real limit, and a $5 hand-sanding block handles it fine for home projects.

The detail sander, a third option

There’s a third family: the triangular detail sander (often called a “mouse” sander), made for tight spots like shutters, spindles and moldings. It doesn’t replace either of the other two and only makes sense if you sand that kind of surface often. Don’t buy it as your first sander.

Corded or cordless?

A corded sander like the DWE6423K runs as long as you do and costs less up front. A cordless one like the Makita XOB01Z is freedom on big pieces and outdoor jobs, but it only makes sense if you already own the batteries. If you’re about to pick a battery platform, start with our best cordless drill guide: the drill usually decides the brand. And connect the dust port to a vacuum: our best shop vac guide explains which filter keeps fine sanding dust out of the air.

Who should skip a random orbit as a first sander

• You mostly sand inside corners, cabinet face frames or window sashes: start with the DeWalt DWE6411 orbital sander, and add a random orbit when the first big tabletop comes along.
• You’re sanding drywall or a ceiling: that’s a job for a long-reach drywall sander, not a handheld one.

FAQ

What’s the difference between an orbital sander and a random orbit sander?

The motion and the shape of the pad. A random orbit sander spins and oscillates a round pad at the same time, so it removes material faster. An orbital sander moves a square pad in small circles: slower, but it reaches corners and is mostly used for finishing.

If I only buy one sander, which should it be?

A random orbit sander, such as the DeWalt DWE6423K ($98.99 on October 27, 2026). It covers most jobs, from stripping and leveling to prep before finishing, and its one weak spot, corners, is easy to handle with a sanding block. The reverse doesn’t work: an orbital sander alone is slow and frustrating on large surfaces.

Why does my random orbit sander leave swirl marks?

Most often because the pad can’t spin freely: pressing too hard stalls the random motion and turns it into a regular circular pattern. Let the weight of the sander do the work. A clogged disc or a worn pad causes the same problem.

Can I use the same sandpaper on both sanders?

No. A random orbit sander takes round 5-inch hook-and-loop discs, usually with 8 dust holes. An orbital sander takes rectangular sheets, often a quarter of a standard 9 × 11-inch sheet (4-1/2 × 5-1/2 in.), held by clamps or hook-and-loop. Check the size and hole pattern before buying a pack.

Do I need a variable-speed sander?

It helps on heat-sensitive materials, like some plastics, varnishes and paints that gum up, where full speed melts more than it sands. On bare wood, full speed is almost always right. It’s a nice extra, not a deal breaker.

How long does a sanding disc last?

Less than you think: a few minutes of actual sanding on resinous softwood like pine, longer on hardwood. A disc that glides instead of biting is worn out, even if it looks fine. A fresh disc sands faster than a more powerful sander with a dull one.

Our verdict 🧰