Start with the coarsest grit that will remove your defect in one pass — usually 36 or 60 for heavy stock removal, 80 for general shaping, 120 for cleanup — then step up one grit at a time until the scratch pattern is where you want it. For most work that means 36 to 60 to 80 to 120 to 180 to 220, and for most work you can stop at 180 or 220. Never skip more than one step in the sequence, because a fine belt removes material slowly and erasing an oversized scratch costs you more time than the belt you skipped would have.
The rest of this page is the detail: a grit chart, progressions by material, and the grading-standard problem that makes "220 grit" mean two different things depending on who printed the belt.
Sanding belt grit chart
| Grit | Category | What it's for | What to expect |
|---|---|---|---|
| 24–36 | Extra coarse | Heavy stock removal, setting knife bevels, weld knockdown, floor sanding, stripping thick coatings | Fastest removal available. Leaves deep, visible gouges that take two or three grits to clear. Use only when you truly need the material gone. |
| 40–50 | Coarse | Aggressive shaping, hogging, rough grinding on steel | Very fast. Still leaves a scratch pattern you'll be chasing for a while. |
| 60 | Coarse | The workhorse starting grit for most metal work and rough wood | Fast, controllable. Best default first grit if you're unsure. |
| 80 | Medium-coarse | Shaping, fairing welds, removing 36/60 scratches, rough dimensioning wood | Moderate removal, much more predictable finish. |
| 100–120 | Medium | Blending, pre-finish on metal, general woodworking | Light removal. This is where you stop shaping and start finishing. |
| 150–180 | Fine | Final wood prep before stain, metal prep before polish or non-woven | Minimal removal. You're refining scratches, not moving stock. |
| 220 | Fine | Final sanding before film finishes, light deburring, pre-buff on steel | Essentially no stock removal. Scratches are hard to see without raking light. |
| 320 | Very fine | Between-coat sanding, fine metal finishing, pre-polish | Removes only the previous scratch tops. |
| 400 | Very fine | Pre-polish on steel, knife blades, plastics, solid surface | Surface starts to reflect. Loading becomes the main issue. |
| 600–800 | Extra fine | Final pre-buff, mirror prep, fine finishing on hardened steel and plastics | No measurable removal. Purely scratch refinement. |
Our catalog covers grits 24 through 800, in dozens of widths and lengths — and we can splice grits and sizes that aren't on the shelf. Shop sanding belts
The grit progression rule, and why it's real
Never skip more than one step in your sequence. So 60 to 120 is acceptable, 60 to 220 is not.
Here's the mechanism. The depth of a scratch scales with the diameter of the particle that cut it — roughly a third of the particle size, though it depends on pressure and material. A 60-grit particle is about 265 microns and leaves furrows tens of microns deep. A 220-grit particle is about 66 microns and removes material at a tiny fraction of the rate.
So when you jump 60 to 220, the 220 belt has to remove the entire depth of every 60-grit furrow, using a grain one quarter the size, at a removal rate maybe one twentieth as fast. You will spend ten minutes with the fine belt to save thirty seconds with the medium one. Worse, you'll be tempted to lean on the fine belt to speed it up — which loads it, heats the part, and leaves you with a burnished surface that won't take stain or won't polish out.
Two corollaries people miss:
- Change direction or orientation at each grit. Sand at a slight angle to the previous pattern, or rotate the part. The moment you can't see any of the previous grit's scratch direction, that grit is done. If you sand in the same direction every time, you genuinely cannot tell whether you've cleared the old scratches.
- Finish each grit before moving up. The most common cause of "my finish looks bad at 400" is a 60-grit scratch that survived five grits because nobody looked at the part under raking light.
FEPA "P" grades vs ANSI/CAMI — the same number is not the same particle
This matters and almost nobody explains it. There are two grading systems in common use:
-
ANSI/CAMI (Coated Abrasives Manufacturers Institute) — the North American standard. Printed as a bare number:
120. -
FEPA (Federation of European Producers of Abrasives) — the European standard, printed with a P prefix:
P120.
Below about 180 grit the two systems track closely. Above 180 they diverge hard, and they diverge in one direction: P-grade is coarser than the CAMI number of the same value.
| Nominal grit | CAMI avg particle (µm) | FEPA "P" avg particle (µm) | Practical note |
|---|---|---|---|
| 60 | 268 | 269 | Effectively identical |
| 80 | 192 | 201 | Close enough to swap |
| 100 | 141 | 162 | P100 noticeably coarser |
| 120 | 116 | 125 | Minor difference |
| 150 | 93 | 100 | Minor difference |
| 180 | 78 | 82 | Minor difference |
| 220 | 66 | 68 | Last grit where they're close |
| 240 | 53 | 58.5 | Divergence begins |
| 320 | 36 | 46 | P320 is roughly CAMI 240 |
| 400 | 23 | 35 | P400 is roughly CAMI 320 |
| 600 | 16 | 26 | P600 is roughly CAMI 400 |
| 800 | 12 | 22 | P800 is roughly CAMI 500–600 |
Average particle diameter; published values vary slightly by source and mineral.
Two things follow:
1. Don't mix systems mid-progression. If you go CAMI 220 to P320, you've stepped from 66 µm to 46 µm — fine. If you go P220 to CAMI 320, you've stepped 68 µm to 36 µm, which is nearly a double-skip and will cost you time. Pick one system for the whole sequence.
2. FEPA grading is tighter. The P system specifies a narrower particle size distribution — fewer oversized grains in the mix. That's why P-graded abrasives often produce a more uniform scratch pattern at the same nominal number, and it's why fine automotive and finishing work is usually specified in P grades.
If a listing doesn't say which system it uses, assume CAMI in North America and ask. We print the grading standard on ours because the difference is the entire point at the fine end.
Grit progressions by material
Wood
80 > 120 > 150 > 180 — stop at 150–180 for oil and stain, 180–220 for film finishes.
Going finer than 220 on most hardwoods is counterproductive: you burnish the surface closed, and stain goes on blotchy. Softwoods and end grain are the exception — end grain drinks stain and benefits from an extra grit. If you're starting from rough sawn stock, add 60 at the front. Aluminum oxide, cloth backing for removal, paper for final passes.
Mild steel and stainless
Stock removal: 36 > 60 > 80 > 120, then non-woven or finer mineral depending on the finish spec.
For a standard architectural #4 satin finish, 120 grit followed by a maroon surface conditioning belt is the usual route. For a #3, stop at 100–120. Keep surface speed down on stainless — it holds heat at the surface and blues easily — and change belts before they're dead. A dull belt on stainless is how you get discoloration and a work-hardened skin that fights the next grit.
Aluminum and other soft metals
80 > 120 > 180 > 220, with loading as the whole battle.
Aluminum welds itself into the belt. Use open coat or stearated aluminum oxide, back off the pressure, and clean the belt with a rubber stick before the loading becomes permanent. Above 220, silicon carbide with a lubricant cuts cleaner than AO. Don't start coarser than 60 unless you're genuinely reshaping — deep scratches in aluminum are disproportionately hard to remove.
Knife bevels
Rough grind before heat treat: 36 > 60 > 120. Post heat treat: 120 > 220 > 400, then hand sanding or 600 > 800 on the machine for a pre-buff surface.
Ceramic for the 36 and 60 work — you have the pressure and the machine for it. Keep a bucket of water at the grinder and quench often after heat treat; a blade that turns colors at the edge has lost its temper and the knife is scrap. Slow the belt down as you go finer. Most blade defects that show up at 400 were put there at 36 and never cleared.
Knife makers run 2x72 hardest of anyone. We convert and splice 2x72 belts in ceramic, zirconia, aluminum oxide, silicon carbide and non-woven materials. Shop knife-making abrasives
Paint and rust removal
Strip: 36 or 60. Fair the surface: 80. Prep for primer: 120 > 180. Feather edges: non-woven or 220.
Match the coarse grit to the coating thickness, not to how fast you want to be done. 36 grit through thin paint puts gouges into the substrate that you'll spend three grits removing. On sheet metal, use light pressure and keep moving — heat warps panels faster than most people expect. On rust, a coarse belt cuts pitting faster than any wire wheel, but pits deeper than your coarsest scratch depth will still be there; you have to either grind past them or fill them.
When to stop sanding and switch
There are three points where a finer coated belt stops being the right tool.
1. When you're no longer removing material. Past about 220 on metal, coated abrasive is refining a scratch pattern, not cutting. If the part still has a high spot at 220, go back down. You cannot fix geometry with fine grit.
2. When you want a uniform look, not a flatter surface. That's the job of surface conditioning non-woven — nylon web with abrasive bonded throughout. Coarse (brown/tan), medium (maroon), and fine (blue/grey) non-woven blend scratch patterns, deburr, and lay down an even satin finish without cutting into the part. They will not remove a scratch, a weld, or a high spot. Reaching for non-woven to remove material is the most common wasted step in a finishing sequence.
3. When the mineral is the limit, not the number. Above 400 on steel, aluminum oxide starts plowing more than cutting. Silicon carbide at the same grit number is harder and sharper, fractures freely, and gives a cleaner cut and a brighter surface — which is why it dominates fine work on steel, plastics, glass, stone, and solid surface.
Surface conditioning belts and discs, in the same sizes as our coated belts. Shop surface-conditioning abrasives
And if your machine takes a size nobody stocks: we convert and splice in-house in Anaheim, 1/4" to 60" wide and up to 400" long, any grit from 24 to 800, low minimums, quote back inside 24 hours, with turnaround confirmed when we quote. Request a custom sanding belt quote
FAQ
What grit sanding belt should I start with? The coarsest grit that removes your defect in one or two passes — and no coarser. For heavy metal removal or setting a knife bevel, 36. For general shaping and weld knockdown, 60. For rough wood, 80. If you're unsure, start at 80: it's slower than 60 but it won't put in damage you'll regret.
Can I skip grits in a sanding progression? You can skip one step — 60 to 120 is fine. Skipping two or more is a false economy, because the finer belt removes material far more slowly than the one you skipped and has to clear the full depth of the coarser scratch. You lose more time at the fine end than you saved at the coarse end.
Is P120 the same as 120 grit? Close, but not identical. P120 is the FEPA (European) grade and averages about 125 microns; CAMI 120 averages about 116 microns. Below 180 the two systems are near enough to interchange. Above 220 they diverge sharply — P400 is roughly equivalent to CAMI 320, and P600 is roughly CAMI 400. Don't mix the two systems inside one progression.
What grit should I use to remove rust or paint? 36 to 60 grit to strip, 80 to fair the surface, then 120 to 180 to prep for primer. Match the coarse grit to the coating thickness — 36 grit through thin paint gouges the substrate and costs you extra grits later. On sheet metal, keep pressure light and the belt moving to avoid warping the panel.
What's the finest grit I need on wood before finishing? 150 to 180 for oil and stain, 180 to 220 for film finishes like lacquer or poly. Going finer burnishes the surface closed and causes blotchy stain absorption. End grain is the exception and takes one extra grit.
Why does my finer belt leave scratches that look worse than the coarse one? Usually one of two things: you skipped too many grits and the fine belt is only polishing the tops of the old furrows, or you leaned on the fine belt to speed it up and loaded it, so it's dragging swarf across the surface. Sand at an angle to the previous pattern so you can actually see when the old scratches are gone.
When should I switch to a non-woven surface conditioning belt? After the coated belts have done all the material removal, typically at 120 to 180 grit. Non-woven blends and evens the scratch pattern and deburrs — it does not remove stock. If the part still has a high spot or a visible weld, go back to a coated belt first.
What grit should I use on knife bevels before heat treat? 36 to set the bevel, 60 to refine it, 120 to finish pre-heat-treat. After heat treat, go 120 to 220 to 400 and up, quenching frequently. Any grind defect left at 36 will still be visible at 400, so clear each grit fully before moving on.