80 versus 120 versus 180 grit

The quick answer: 80 grit removes material fastest, 120 grit smooths and refines, and 180 grit prepares a surface for paint, stain, or a final finish. For many wood projects, the practical progression is 80 grit only when needed, followed by 120 grit and then 180 grit.

What the grit numbers mean

Grit describes the size of the abrasive particles on the sandpaper. A lower number has larger, more aggressive particles; a higher number has smaller particles and leaves a finer scratch pattern.

This means:

• 80 grit: Fast cutting and heavy smoothing
• 120 grit: General-purpose sanding and scratch refinement
• 180 grit: Fine smoothing and finish preparation

Grit ratings are not perfectly interchangeable between every standard. CAMI and FEPA systems can differ, so compare the stated rating and intended use rather than assuming every brand performs identically.

When to use 80 grit

Choose 80 grit when you need to remove material quickly. It is useful for:

• Removing old finish, paint, or varnish
• Leveling rough boards or uneven wood
• Smoothing pronounced scratches, ridges, or tool marks
• Removing minor surface damage before finer sanding
• Shaping wood edges and rough profiles

80 grit can leave deep scratches, especially on softwood or veneered surfaces. Avoid starting with it on delicate veneer, thin paint layers, or already-smooth wood unless you need its extra cutting power.

Use light, even pressure. Pressing harder can create uneven grooves, clog the abrasive, and make it harder for the next grit to remove the scratches.

When to use 120 grit

120 grit is the most useful middle step for many woodworking and refinishing jobs. Use it to:

• Smooth the scratches left by 80 grit
• Prepare bare wood for many paints and stains
• Refine planed, cut, or repaired surfaces
• Remove light surface imperfections
• Sand between some coats of finish when the product instructions allow it

If the surface is already fairly smooth, 120 grit may be the right starting point. Starting with a coarser grit than necessary wastes material and increases the chance of visible scratches.

When to use 180 grit

180 grit produces a finer scratch pattern and is commonly used for final surface preparation. It works well for:

• Final sanding of bare wood before finishing
• Removing the remaining 120-grit scratches
• Light smoothing between coats of paint, sealer, or finish
• Preparing surfaces that must feel smooth without being polished
• Refining edges and details after heavier sanding

Do not assume that finer is always better. Over-sanding can burnish or polish some woods, reducing how evenly they absorb stain or finish. Follow the coating manufacturer's preparation instructions, particularly when sanding between coats.

Which grit should you start with?

Use the least aggressive grit that can solve the surface problem:

These are starting points, not requirements. Test an inconspicuous area when working on veneer, stained wood, painted surfaces, or an unfamiliar coating.

Should you use all three grits?

Not always. Use the shortest sequence that removes the previous scratch pattern:

• 80 → 120 → 180: Best for rough surfaces or heavy finish removal
• 120 → 180: Suitable for many general wood-sanding jobs
• 180 only: Suitable for light smoothing or final preparation when the surface is already even

Avoid jumping directly from 80 to 180 when possible. The finer abrasive may take a long time to remove the deeper 80-grit scratches. Conversely, using 80 grit on a surface that only needs light smoothing creates unnecessary work.

Sanding technique affects the result

Regardless of grit, technique matters:

1. Sand with the grain on visible wood surfaces.
2. Use even strokes and moderate pressure.
3. Let the abrasive do the cutting instead of forcing it into the surface.
4. Remove dust before changing grits.
5. Inspect under good lighting before moving to the next grit.
6. Change or clean clogged paper rather than pressing harder.

On flat surfaces, a sanding block helps distribute pressure. A flexible sheet or sanding sponge can conform better to profiles, corners, and trim, but it may be easier to round over sharp edges.

Choosing sheets, discs, or sponges

The grit number is only part of the decision. Choose the format that matches the tool and surface:

• Sheets: Useful for hand sanding, sanding blocks, and detail work
• Discs: Designed for compatible random orbital or rotary sanders; verify the diameter and hole pattern
• Sanding sponges: Useful on edges, contours, and light hand sanding; they may not remove material as quickly as rigid paper
• Hook-and-loop abrasives: Convenient for compatible power sanders and easier grit changes

For power sanding, confirm the abrasive's backing and attachment method match your tool. A disc with the wrong size or hole pattern may not fit correctly or collect dust effectively.

Common mistakes

Starting too coarse

Using 80 grit on a nearly smooth surface can create scratches that require several additional steps to remove. Start with 120 or 180 when only light refinement is needed.

Finishing too coarse

Stopping at 80 or 120 may leave visible scratches beneath paint, stain, or clear finish. Use 180 when the coating instructions and surface require a finer preparation.

Skipping dust removal

Loose abrasive dust can interfere with inspection and contaminate paint or finish. Vacuum or wipe according to the coating manufacturer's instructions before applying the next product.

Sanding through veneer

Thin veneer can be removed quickly, especially with 80 grit or a power sander. Use a finer grit, light pressure, and frequent inspections near edges and repaired areas.

Expecting 180 grit to level defects

180 grit is for refinement, not major leveling. Return to 80 or 120 grit when necessary, then work back through the sequence so the deeper scratches are removed.

Bottom line

Choose 80 grit for aggressive removal, 120 grit for general smoothing, and 180 grit for fine preparation or between-coat sanding. For a typical rough-wood project, use 80 only if needed, then move through 120 to 180. For already-smooth wood, begin with 120 or 180 instead of creating extra scratches with a coarse abrasive.