Best Walnut Shells for Blasting (2026): 5 Picks for Cabinets and Tumblers
5 crushed walnut shell media for blasting and tumbling, from 12-20 coarse grit to 60 mesh fine, compared by grit size, hardness and bag weight.
On this page
Top picks at a glance
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- 1
Best OverallGRITSMITH 18-409.6/10View on Amazon - 2
Best for BrassMineral Supply 18/409.6/10View on Amazon - 3
Best CoarseINTERACTIVIA 12-209.5/10View on Amazon - 4
Best Fine GritHOLDWIN 60 Fine9.4/10View on Amazon
A carburetor body caked in carbon, a set of brass cases dull from the range, an aluminum intake valve black with deposits: each needs an abrasive that cuts the grime without cutting the metal underneath. The best walnut shells for blasting are crushed shells sized to the job, soft enough to leave aluminum and brass alone and tough enough to strip paint, grease, rust and carbon.
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Quick picks
- Best Overall GRITSMITH 18-40: 18-40 grit, 0.42 mm to 1 mm, Mohs 4.5-5, silica-free and reusable Check price on Amazon
- Best for Brass Mineral Supply 18/40: California English walnut in a resealable jar, sized for brass tumbling Check price on Amazon
- Best Coarse INTERACTIVIA 12-20: 12-20 grit in an 8 lb bag, rated for 8-10 cycles or more Check price on Amazon
- Best Fine Grit HOLDWIN 60 Fine: 60 mesh, 0.25 mm fine grit for polishing and finishing Check price on Amazon
Picks for the garage
GRITSMITH 18-40 Grit Premium Crushed Walnut Shell
18-40 grit crushed walnut shell media, 0.42 mm to 1 mm, Mohs 4.5-5, in a 5 lb bag for blasting, tumbling and brass case cleaning.
Pros
- 18-40 grit at 0.42 mm to 1 mm for blasting and tumbling
- Mohs 4.5-5, hard enough to strip carbon and gentle on aluminum and brass
- Silica-free, non-toxic and reusable over multiple cycles
- Cleans paint, grease, rust, dirt and carbon from soft metals
Cons
- No warranty term is stated
- No resealable packaging is stated
- The listing also covers pincushion filler and craft uses
- No reuse cycle count is stated
Industrial Mineral Supply Crushed Walnut Shell
18/40 medium grit California English walnut shell media, 5 lb in a resealable jar, for brass tumbling, blasting and intake valve carbon cleaning.
Pros
- California English walnut, screened to a consistent 18/40 mesh
- Resealable wide-mouth PET jar stores dry and pours clean
- Safe on aluminum, brass, chrome, wood, fiberglass and engine parts
- 5 lb is a full charge for most benchtop vibratory tumblers
Cons
- No warranty term is stated
- Mohs 3-4 is softer than the 4.5-5 other listings state
- No particle size in millimeters is stated
- No reuse cycle count is stated
8 lbs or 3.6 kg Ground Walnut Shell Media 12-20
12-20 grit coarse ground walnut shell media, 1600-940 microns, in an 8 lb bag for heavy-duty blasting and stripping.
Pros
- 12-20 coarse grit for heavy-duty cleaning and stripping
- 8 lb bag, the largest here
- Rated for 8-10 cycles or more with low pressure
- Natural, biodegradable walnut shells with no silica dust
Cons
- No warranty term is stated
- The size reads 1600-940 microns, largest first
- No Mohs hardness is stated
- The title spells the grit 'Medium Course'
HOLDWIN 60 Fine Grit Walnut Shell Media
60 mesh fine grit walnut shell media, 0.25 mm, in a 5 lb bag for polishing, deburring and engine carbon cleaning.
Pros
- 60 mesh, 0.25 mm fine grit for polishing and finishing
- Mohs 4.5-5, gentle on soft metals, wood and plastic
- Suits blasting, tumbling, deburring and engine carbon cleaning
- Reusable over multiple cycles
Cons
- No warranty term is stated
- No silica-free claim is stated
- No reuse cycle count is stated
- The listing also covers pincushion filler and anti-slip coatings
5 lbs 18/40 Grit Ground Walnut Shells,Fine Grit
18/40 grit ground walnut shells, 0.42-1mm, in a 5 lb bag for tumbling, blasting, polishing and deburring.
Pros
- 18/40 grit at 0.42-1mm for blasting and tumbling
- All-natural walnut shells, non-toxic
- Polishes surfaces without damaging the substrate
- Suits tumbling, blasting, polishing and deburring
Cons
- No warranty term is stated
- No Mohs hardness is stated
- No surfaces are named beyond the uses
- The listing is a single short bullet with no packaging detail
Compared on paper
| Model | Shop Score | Grit | Particle size | Mohs hardness | Bag weight | Reusable |
|---|---|---|---|---|---|---|
| GRITSMITH 18-40 | 9.6/10 | 18-40 | 0.42 mm to 1 mm | 4.5-5 | 5 lb | Yes |
| Mineral Supply 18/40 | 9.6/10 | 18/40 | Not stated | 3-4 | 5 lb | Yes |
| INTERACTIVIA 12-20 | 9.5/10 | 12-20 | 1600-940 microns | Not stated | 8 lb | 8-10 cycles or more |
| HOLDWIN 60 Fine | 9.4/10 | 60 mesh | 0.25 mm | 4.5-5 | 5 lb | Yes |
| HDURCIR 18/40 | 9.4/10 | 18/40 | 0.42-1mm | Not stated | 5 lb | Not stated |
Specifications are manufacturer rated, as published on each listing and collected 9 November 2026.
How the scores work
The Shop Score weighs 5 factors: performance (grit range, particle size, surfaces cleaned), build quality (screening, consistency, packaging), value (bag weight and specs for the money), safety (silica-free, non-toxic, low dust where stated) and warranty (months and coverage). A factor the listing does not state scores zero.
| Product | Shop Score | Perf. /35 | Build /25 | Value /25 | Safety /10 | Warranty /5 |
|---|---|---|---|---|---|---|
| GRITSMITH 18-40 | 9.6 | 30 | 21 | 20 | 5 | 0 |
| Mineral Supply 18/40 | 9.6 | 30 | 21 | 20 | 5 | 0 |
| INTERACTIVIA 12-20 | 9.5 | 29 | 20 | 21 | 4 | 0 |
| HOLDWIN 60 Fine | 9.4 | 29 | 20 | 20 | 0 | 0 |
| HDURCIR 18/40 | 9.4 | 24 | 18 | 19 | 3 | 0 |
Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score.
What the listings tell you
All 5 listings state a grit size and a bag weight. 3 state a Mohs hardness figure, and the figures differ: GRITSMITH and HOLDWIN state 4.5-5, while Industrial Mineral Supply states 3-4. 3 state a particle size in millimeters, and only INTERACTIVIA states a reuse cycle count. No listing states a warranty term.
Buying guide: choosing the best walnut shells for blasting
Grit size and particle size
12-20 grit is the coarse end: INTERACTIVIA sizes it at 1600-940 microns for heavy-duty stripping. 18-40 grit is the middle ground, at 0.42 mm to 1 mm on GRITSMITH and HDURCIR, for general blasting and tumbling. 60 mesh is the fine end: HOLDWIN sizes it at 0.25 mm for polishing and finishing.
Mohs hardness and soft metals
GRITSMITH and HOLDWIN state a Mohs hardness of 4.5-5, while Industrial Mineral Supply states 3-4, so the figures differ between listings. GRITSMITH and Industrial Mineral Supply name aluminum as a safe surface, and Industrial Mineral Supply adds brass, chrome, wood, fiberglass and engine parts, cleaned without pitting or warping. For aluminum work specifically, see the best media for blasting aluminum roundup.
Bag weight and packaging
4 of the 5 bags hold 5 lb, and INTERACTIVIA holds 8 lb. Industrial Mineral Supply ships in a resealable wide-mouth PET jar with a screw cap, so the media stores dry and pours clean. The other listings state no packaging, so check the bag before the first job.
Blasting, tumbling and carbon cleaning
All 5 listings cover blasting and tumbling. GRITSMITH, Industrial Mineral Supply and HOLDWIN name engine carbon cleaning, and Industrial Mineral Supply names intake valve carbon cleaning in particular. Industrial Mineral Supply also names gun parts and vintage restoration, and GRITSMITH names brass case cleaning.
Reuse and dust
GRITSMITH, Industrial Mineral Supply and HOLDWIN all say the media can be reused, and INTERACTIVIA states 8-10 cycles or more with low pressure. GRITSMITH and INTERACTIVIA state no silica dust, and Industrial Mineral Supply states low dust. HDURCIR states no reuse or dust figure.
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Garage Fit Check
- A 5 lb bag is a full charge for most benchtop vibratory tumblers, per the Industrial Mineral Supply listing.
- The Industrial Mineral Supply jar is a resealable wide-mouth PET jar with a screw cap, so the media stores dry between jobs.
- INTERACTIVIA lists a loose bulk density of about 40-50 lb per cubic foot and a bag size of 12.0 x 9.0 x 4.0 inches, so check shelf space before ordering the 8 lb bag.
- Check the grit before the first job: 12-20 for heavy-duty stripping, 18-40 for general blasting and tumbling, 60 mesh for fine polishing.
FAQ: garage tools
What grit walnut shell is best for blasting?
18-40 grit suits general blasting and tumbling, 12-20 grit suits heavy-duty stripping, and 60 mesh suits fine polishing and finishing.
Are walnut shells safe on aluminum?
GRITSMITH and Industrial Mineral Supply name aluminum as a safe surface. Industrial Mineral Supply states its 3-4 Mohs media cleans aluminum without pitting or warping.
Can walnut shells clean carbon from intake valves?
Industrial Mineral Supply names intake valve carbon cleaning, and HOLDWIN names engine carbon cleaning. GRITSMITH also states its media strips carbon buildup.
How many times can walnut shell media be reused?
GRITSMITH, Industrial Mineral Supply and HOLDWIN all say the media can be reused over multiple cycles. INTERACTIVIA states 8-10 cycles or more with low pressure.
What is the difference between 18-40 and 60 mesh walnut shells?
18-40 grit is 0.42 mm to 1 mm, a medium grit for blasting and tumbling. 60 mesh is 0.25 mm, a fine grit for polishing and finishing.
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