What is the difference between CAMI and FEPA grit ratings?

CAMI (Coated Abrasive Manufacturers Institute) is the US standard, while FEPA (Federation of European Producers of Abrasives) is the European standard denoted with a 'P' prefix. While they use similar numbers, they measure particle size differently. FEPA grades tend to have tighter tolerances. For example, CAMI 220 grit is roughly equivalent to FEPA P220, but at finer grits the standards diverge more significantly.

What grit sandpaper should I use for wood finishing?

For wood finishing, start with 80-100 grit to remove mill marks and imperfections, progress to 120-150 grit for shaping, then 180-220 grit before staining. For a smooth finish before clear coats, sand to 320-400 grit. Between finish coats, use 320-400 grit to scuff the surface for adhesion.

What does the micron rating on sandpaper mean?

The micron rating indicates the average particle size of the abrasive material. One micron equals one-thousandth of a millimeter. Lower micron numbers mean finer abrasives. For example, 40 grit sandpaper has particles around 425 microns, while 2000 grit has particles around 10 microns. Micron ratings provide a more precise measurement than grit numbers.

Can I skip grits when sanding?

You can skip one grit level in most cases, but skipping more will leave visible scratches from the previous grit. The general rule is to not more than double the grit number between steps. For example, going from 80 to 150 is acceptable, but jumping from 80 to 220 will leave scratch patterns. Skipping grits also means more work at each step to remove the previous scratches.

Sandpaper Grit Chart 2026 | CAMI vs FEPA Conversion

Complete Grit Conversion Chart

This chart shows the relationship between CAMI (US), FEPA (European P-grade), and micron measurements. Use it to find equivalent grits when working with international products.

CAMI (US)	FEPA (P-Grade)	Microns	Category	Common Uses
40	P40	425	Extra Coarse	Heavy material removal, paint stripping, rough shaping
50	P50	348	Extra Coarse	Aggressive stock removal, floor sanding first pass
60	P60	268	Coarse	Removing old finishes, heavy rust, initial shaping
80	P80	190	Coarse	Removing mill marks, rough sanding, initial smoothing
100	P100	162	Medium	General purpose sanding, preparing for finer grits
120	P120	125	Medium	Removing 80-grit scratches, pre-stain prep for softwoods
150	P150	100	Medium	Final sanding before primer, general woodworking
180	P180	82	Fine	Final bare wood sanding, between primer coats
220	P220	68	Fine	Final sanding before stain/finish, scuffing between coats
240	P240	58.5	Fine	Sanding sealers, light scuffing
280	P280	52.2	Fine	Between finish coats, smoothing filled grain
320	P320	46.2	Very Fine	Final sanding before topcoat, automotive primer
360	P360	40.5	Very Fine	Between finish coats, pre-polish prep
400	P400	35	Very Fine	Wet sanding, final prep before clear coat
500	P500	30.2	Very Fine	Wet sanding automotive finishes
600	P600	25.8	Extra Fine	Wet sanding, polishing prep, metal finishing
800	P800	21.8	Extra Fine	Wet sanding clear coats, fine metal work
1000	P1000	18.3	Ultra Fine	Wet sanding before buffing, headlight restoration
1200	P1200	15.3	Ultra Fine	Pre-polish sanding, removing orange peel
1500	P1500	12.6	Ultra Fine	Final wet sanding before polish
2000	P2000	10.3	Ultra Fine	Final sanding, mirror finish prep
2500	P2500	8.4	Ultra Fine	Color sanding, high-gloss prep
3000	P3000	6.5	Ultra Fine	Mirror finish prep, scratch removal

Note on Standards

CAMI and FEPA standards align closely at coarser grits but diverge at finer grits. FEPA P-grades have tighter particle size tolerances, meaning more consistent scratch patterns. When precision matters, FEPA-graded products often deliver more predictable results.

Grit Progression Guides

Proper grit progression is essential for efficient sanding and quality results. Skipping too many grits leaves visible scratches; using too many wastes time. Here are recommended progressions for common applications.

Wood Finishing

80 Remove mill marks, flatten surfaces, initial shaping

120 Remove 80-grit scratches, refine shape

150 Smooth surface, prepare for stain (softwoods)

180 Final bare wood sanding (most projects)

220 Pre-stain for hardwoods, between finish coats

320-400 Between topcoats, ultra-smooth finish

Tip: For open-grain woods like oak, stop at 180 grit to allow stain penetration. For closed-grain woods like maple, you can go to 220 or higher.

Metal Finishing

60-80 Remove rust, scale, weld spatter, heavy grinding

120 Remove coarse scratches, blend welds

180 Refine surface, prep for primer

220-320 Final prep before paint or powder coat

400-600 Brushed finish, pre-polish prep

800-2000 Mirror polish prep (with compound)

Tip: Use silicon carbide or ceramic abrasives for metal. Always sand in one direction for a consistent grain pattern on decorative finishes.

Automotive Paint Prep

80 Strip old paint, remove rust, body filler shaping

180 Feather edges, smooth filler

320 Final bare metal/filler prep before primer

400-600 Sand primer, prep for basecoat

800-1000 Wet sand before clear coat

1500-2000 Color sand clear coat before buffing

Tip: Always wet sand at 600 grit and above. Use a sanding block to maintain flat surfaces. Guide coat helps reveal low spots.

Drywall Finishing

100-120 First coat sanding, knock down high spots

120-150 Second coat sanding, smooth transitions

150-180 Final sanding before primer

180-220 Between primer coats (if needed)

Tip: Use sanding screens or mesh abrasives for drywall - they resist clogging. A pole sander with proper lighting at an angle reveals imperfections.

Sandpaper Abrasive Types

Different abrasive materials excel at different tasks. Choosing the right type can dramatically improve your results and reduce costs.

Aluminum Oxide

Most Common

The most versatile and widely used abrasive. Brown or tan in color. Fractures during use to expose fresh cutting edges, making it self-renewing.

Best for: Wood, metal, painted surfaces
Hardness: 9 on Mohs scale
Pros: Affordable, long-lasting, widely available
Cons: Not ideal for very hard materials
Cost: Low to moderate

Silicon Carbide

Hardest

Harder and sharper than aluminum oxide. Black or dark gray in color. Fractures into sharp splinters that cut aggressively.

Best for: Metal, glass, stone, wet sanding, automotive finishes
Hardness: 9.5 on Mohs scale
Pros: Cuts faster, excellent for wet sanding, works on hard materials
Cons: Wears faster on wood, more expensive
Cost: Moderate

Ceramic Alumina

Premium

Engineered ceramic particles that micro-fracture to stay sharp longer. Blue, purple, or reddish-brown in color. Premium performance for demanding applications.

Best for: High-pressure sanding, hardwoods, metals, aggressive stock removal
Hardness: 9+ on Mohs scale
Pros: Lasts 3-6x longer than aluminum oxide, stays sharp, cuts cool
Cons: Higher initial cost
Cost: High (but cost-effective for heavy use)

Garnet

Natural

Natural mineral abrasive. Reddish-brown in color. Dulls rather than fracturing, which can leave a smoother surface.

Best for: Hand sanding bare wood, final finishing
Hardness: 7-7.5 on Mohs scale
Pros: Leaves smooth surface, won't embed in wood grain, natural
Cons: Wears out faster, limited grit range
Cost: Low to moderate

Zirconia Alumina

Heavy Duty

Extremely durable synthetic abrasive. Blue-gray or green in color. Designed for high-pressure applications and power tools.

Best for: Metal grinding, weld removal, heavy stock removal
Hardness: 9+ on Mohs scale
Pros: Very long life, handles heat well, aggressive cutting
Cons: Too aggressive for fine work, higher cost
Cost: Moderate to high

Choosing the Right Abrasive

For general woodworking, aluminum oxide handles 90% of tasks. Invest in ceramic for belt sanders or drum sanders where you're doing heavy stock removal. Use silicon carbide for wet sanding and metal finishing. Garnet is ideal for hand sanding final finishes where you want the smoothest possible surface.

Sandpaper Backing Types

The backing material affects flexibility, durability, and appropriate applications. Paper backings use letter grades (A-F) to indicate weight and stiffness.

Paper Backing Weights

Weight	Thickness	Flexibility	Durability	Best Uses
A-Weight	Lightest	Most flexible	Low	Hand sanding contours, light finishing
B-Weight	Light	Very flexible	Low-Medium	Hand sanding, light power sanding
C-Weight	Medium	Moderate	Medium	General purpose, hand and power sanding
D-Weight	Medium-Heavy	Less flexible	Medium-High	Power sanders, light industrial
E-Weight	Heavy	Stiff	High	Belt sanders, drum sanders, industrial
F-Weight	Heaviest	Very stiff	Highest	Wide belt sanders, heavy industrial

Cloth Backings

J-Weight (Jeans)

Lightweight, flexible cloth backing. Good for contour sanding and hand work. More durable than paper but still flexible enough for curves.

X-Weight

Heavy-duty cloth backing. Standard for sanding belts. Excellent durability and tear resistance. Handles high-pressure applications.

Y-Weight

Extra heavy polyester cloth. Maximum strength for wide belt sanders and extreme applications. Often used with ceramic or zirconia abrasives.

Other Backing Types

Film Backing

Polyester film provides the most consistent thickness and flattest surface. Used for ultra-fine grits (1000+) where uniformity is critical. Common in automotive finishing and precision applications.

Mesh/Screen

Open mesh construction allows dust to pass through, dramatically reducing clogging. Ideal for drywall sanding and dusty applications. Works with hook-and-loop systems.

Foam Backed

Thin foam layer between abrasive and backing provides cushioning. Conforms to curves and contours. Popular for automotive and woodworking detail work.