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Grit profile

320grit sandpaper

Very Fine

Between top-coat layers. Glass-smooth feel.

320 grit in other scales

If the pack says 320 (CAMI, most US paper)

~36 µmAbout the same as P400.

If it says P320 (FEPA, Festool, Mirka, Norton 3X)

~46.2 µmBetween CAMI 240 and 320.P320, converted →

Sizes are average particle diameters from the published CAMI and FEPA tables. Full ladder in the grit chart; any grade on any scale in the grit converter.

What 320 grit is for

320-grit is finish-coat territory. It’s used between coats of lacquer, polyurethane, or shellac to knock down dust nibs and provide tooth for the next coat. On bare wood, 320 starts to over-polish and reduce stain absorption.

Projects at 320 grit

  • · De-nibbing between coats of clear finish
  • · Wet sanding sealer coats on guitars and instruments
  • · Final pass on metal before clear-coating
  • · Smoothing dried CA glue
  • · Light scuff between paint coats on auto-body

Abrasive materials

  • · silicon carbide (most common at this grit)
  • · aluminum oxide
  • · ceramic

Common mistake

320 between coats works best when the previous coat is fully cured. Sand too early and the abrasive gums up immediately.

← 220 grit (the step before)400 grit (the step after) →

Top pick at 320

3M Pro Grade Precision Assorted Pack

Five grits. One box. Everything you need to finish what you started.

Check priceReview

Catalog fit

22

Current SKU matches in this grit lane.

Common forms

3

Forms represented here, led by discs.

Head to head

4

Comparison pages currently touching this stage of the sanding climb.

Use this grit when

The surface still needs this stage.

  • · Between top-coat layers. Glass-smooth feel.
  • · This is refinement territory. It improves the surface that is already close rather than rescuing a rough one.
  • · On this site, 320 grit shows up most around fine furniture, 6-inch orbital sanders, auto-body, and dust-free sanding.

Skip this grit when

The job is earlier or later than this.

  • · Skip this grit if the surface still has deep scratches, filler ridges, or obvious machine marks from coarse paper.
  • · Skip the urge to jump straight here from a very coarse grit; the scratch pattern underneath will usually survive the shortcut.

Recommended at this grit.

Head to head

Comparisons in this lane.

Norton 3X Sheet Sandpaper, 220 Grit (20-pack) vs. 3M Pro Grade Precision Assorted Pack

One grit done right, or five grits done well.

Read the breakdown →

Mirka Gold 5-inch Hook & Loop Disc Assortment vs. Diablo 5-inch ROS Discs, 120 Grit (50-pack)

Finnish precision or American volume.

Read the breakdown →

3M Pro Grade Precision Assorted Pack vs. Gator Finishing Multi-Grit 9x11 Sandpaper Pack

Both cover the range. One holds up longer.

Read the breakdown →

Mirka Gold 5-inch Hook & Loop Disc Assortment vs. 5-Inch Random Orbital Sander + Disc Starter Bundle

You either have the sander or you don't.

Read the breakdown →

Questions people ask

The practical part.

What is 320 grit actually for?

320 grit is for between top-coat layers. glass-smooth feel. This is refinement territory. It improves the surface that is already close rather than rescuing a rough one.

What should come before and after 320 grit?

The safe lane is usually 220 -> 320 -> 400. You can stretch that a little on easy material, but large jumps usually leave scratches behind.

Which forms make the most sense at 320 grit?

On UltraRough, this grit shows up most in discs, sheets, and sponges. That reflects where shoppers usually need this cut level in the real world.

Keep moving

Follow the climb.

220 gritThe step before 320 grit.400 gritThe next step after 320 grit.DiscsSee discs that commonly show up in this lane.SheetsSee sheets that commonly show up in this lane.SpongesSee sponges that commonly show up in this lane.Use the grit selectorStart from the project instead of the number.Sandpaper grit chart: coarse to fineThe full range mapped to projects — every grit from 40 to 3000.Find the right grit for your projectTell us the job; we'll tell you where to start and where to stop.
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