220 vs 240 Grit Sandpaper: Which Fine Step Fits the Finish?

The useful difference is small, so let the finish decide

Between 220 and 240 grit, neither grade is a universal “final” choice. On the same abrasive grading system and product family, 240 is the finer step, so it usually cuts a little more slowly and leaves a slightly finer scratch pattern. The gap is modest. It will not erase deep 180-grit scratches merely because its number is higher, and it may add work where a finish manufacturer already specifies 220.

Choose 220 when the surface still needs meaningful refinement and the next coating or finish accepts that scratch. Choose 240 when the surface is already even, the specification permits it, and the goal is a lighter final refinement. If the labels come from different grading systems or abrasive constructions, compare complete products rather than assuming the printed numbers are directly interchangeable.

Use the existing scratch as the first filter

Wipe or vacuum away loose dust and inspect under light from two directions. A surface that contains occasional deeper lines is not ready for a finer grade. Circle one of those lines outside the working area, then sand a small test patch with the current grade. If the line remains while the surrounding surface becomes smoother, returning to the last effective step is usually faster than polishing around it.

A uniform 220-grit pattern can be ready for a specified finish. A mixed pattern of 180 and 220 is not. Likewise, 240 should replace the 220 pattern across the whole test area before you treat it as a completed 240 step. Touch can detect a ridge, but it cannot reliably distinguish two closely spaced fine grades.

Run a two-patch finish test

Prepare two pieces of matching scrap, or two adjacent test areas that can be refinished if needed. Keep the abrasive brand and construction, support, stroke pattern, pressure, and sanding time as consistent as practical. Finish one at 220. Refine the second completely with 240. Clean both by the coating manufacturer’s approved method and apply the same finish at the same spread rate.

After the finish has cured as specified, compare the two patches in normal and raking light. Look for visible scratches, stain color, adhesion, leveling, and edge definition. Do not select 240 merely because the dry sanded patch looks shinier; dry shine can come from burnishing, loading, or residue and is not proof of a better finish substrate.

On bare wood, over-sanding can reduce how strongly some stains color the surface, particularly when species, grain direction, and product chemistry vary. On primer or a cured coating, the required final grade may be set by the coating maker to balance scratch removal and mechanical key. The sample settles that question more reliably than a generic grit ladder.

Match the sheet to the verified endpoint

For a small controlled trial, eQualle 220-grit sheets in a 10-sheet pack and 240-grit sheets in a 10-sheet pack provide separate 9 × 11 sheet options. The same 240-grit pack offers that identical pack through a different checkout. Pack size does not determine the correct endpoint; the finish schedule and test result do.

Compare quantities in the 220-grit collection and 240-grit collection only after choosing the grade. For the broader role of each step, see the 220-grit uses and finish checks and the 240-grit uses and next steps.

Keep the comparison controlled at edges and profiles

Use a flat block on a flat face and a support shaped for an existing contour. Folded paper under fingertips concentrates pressure and can round an edge before the grade difference becomes meaningful. Make fewer passes on corners and raised profiles, then inspect them dry. If a finish is already thin at an edge, masking that edge during the broad-face test can prevent an accidental breakthrough.

Change one variable at a time. Switching from a firm block with 220 to a soft pad with 240 changes both grade and support; a smoother-looking result cannot reveal which change mattered. Label the test patches so the comparison survives cleanup and finishing.

A brief grit-selection reminder

Stop when the next process has what it needs

The winning grade is the one that removes the previous scratch, preserves the shape, and meets the next product’s preparation requirement. If both samples finish equally well, 220 may be the efficient stopping point. If the 240 sample gives a visibly cleaner result without weakening the specified preparation, use 240. The number alone cannot answer what the coating, material, and inspection together can.