Discs
Pro
Grit · 400
Festool Granat 5-Inch Disc, 400 Grit (25-pack)
Extra fine. Holds its edge past where everything else gave up.
FEPA P-grade · Converted
P400 in CAMI grit and microns.
P400 paper averages about 35 µm on the FEPA table. On the US CAMI scale that is about CAMI 320. A sheet printed plain "400" is a different animal: about 23 µm, nearer P800. If the instructions say P400 and the pack has no P on it, reach for the CAMI number, not the digits.
- Avg. particle
- ~35 µm
- FEPA table
- Nearest CAMI
- 320
- by particle size
- Plain "400"
- ~23 µm
- CAMI 400 ≈ P800
- 3M Trizact
- A45
- 3M’s own pairing
What P400 is for
Leveling primer before color; fine finishing between coats.
- 3M Trizact A45 / P400Pre-polish on metal; primer leveling.
- Norton 3X P400Fine between-coat work on finish.
- Festool Granat P400Fine between-coat work.Check price →
Either side of P400
The neighborhood.
At this grade
Paper we link at P400.
Questions people ask
What is P400 in CAMI grit?
About 320. P400 averages 35 microns on the FEPA table and CAMI 320 averages 36, so the scratch is close to the same.
How many microns is P400 sandpaper?
About 35 microns average particle diameter, per the FEPA P-grade table (ISO 6344).
Is P400 the same as 400 grit?
No. P400 averages 35 microns; a sheet printed plain "400" on the CAMI scale averages 23, which is closer to P800. The CAMI sheet is the finer of the two.
What Trizact grade is P400?
3M pairs P400 with Trizact A45 in its Trizact brochure. Don't read the A-number as microns: 3M's own pairings put A45 at P400, which averages 35 microns on the FEPA table.
Convert any other grade, from CAMI, microns or a Trizact A-number, on the grit converter.
Sizes are average particle diameters from the published FEPA (ISO 6344) and CAMI (ANSI B74.12/B74.18) tables. "Nearest" means within 10%; otherwise both neighbors are shown. Trizact pairings are 3M's own. Sources: Wikipedia, "Sandpaper" grit table (rev. 1127917881); Klingspor coated abrasives grit chart; 3M Trizact A-to-P table.