P800 sandpaper
21.8 µm grain
P800 (FEPA) · about 500 grit (CAMI) · 0.022 mm average particle
What P800 is for
Between coats on a high-gloss finish, and the start of the polishing range rather than the sanding one.
The two scales
| FEPA (European) | P800 |
| CAMI (American) | about 500 |
| Average grain | 21.8 µm |
| Scales agree here? | No — P800 is about 60% coarser than a CAMI 800 |
A packet marked 800 in the United States is finer than one marked P800 in Europe. The P prefix is the tell, and it is easy to miss on a label — which is why a finishing schedule copied from an American source and followed with European paper comes out coarser than intended at every step.
Nearby grits
| FEPA | CAMI | Grain | Typically |
|---|---|---|---|
| P400 | 320 | 35 µm | The clearest case of the mismatch |
| P500 | 360 | 30.2 µm | Fine finishing and light wet sanding |
| P600 | 400 | 25.8 µm | Wet sanding paint and polishing metal |
| P800 | 500 | 21.8 µm | Between coats on a high-gloss finish, and the start of the polishing range rather than the sanding one |
| P1000 | 600 | 18.3 µm | Wet sanding clear coat before compounding |
| P1200 | 800 | 15.3 µm | Removing orange peel from paint |
| P1500 | 1000 | 12.6 µm | Final wet sanding before machine polishing on automotive paint |
Frequently asked questions
Is P800 the same as 800 grit?
No. P800 is roughly CAMI 500 — the American 800 grit is finer than the European P800. The two scales agree up to about 180 and separate above it, so at this end a packet marked 800 and a packet marked P800 are genuinely different papers.
What grain size is P800?
An average grain of 21.8 µm — 0.022 mm. That figure is what the P number is defined by, which is why it is the reliable way to compare across scales.
What is P800 used for?
Between coats on a high-gloss finish, and the start of the polishing range rather than the sanding one.
What comes before and after P800?
Coming up from coarse, P600 (25.8 µm) and then this; the next step finer is P1000 at 18.3 µm. Skipping more than one step leaves scratches the finer paper cannot remove — the usual cause of a surface that looks fine dry and terrible once finish goes on.