Harder garnet.
Cleaner steel.
GRM Garnet is 98% almandine garnet for abrasive blasting, waterjet cutting and water filtration. Every blasting grade reaches the top Sa 3 blast finish, with chlorides 40–60% below the ISO limit.
GRM Garnet range
Ten graded sizes, coarse 2/4 to fine 120#
- 98% almandine
- 7.5–8.0 Mohs
- Specific gravity 4.00
- Sa 3 on every blasting grade
- 10–15 ppm chlorides
- 100–150 µS/cm conductivity
- 0.5% free silica
- Radioactivity not detectable
- Non-hygroscopic
- Sub-angular grains
Every grain does the work. 98% almandine.
“Garnet” is a family name, not a specification. Two bags with the same label can perform very differently on the job. GRM Garnet is almost pure almandine, the iron–aluminium garnet that ranks among the hardest and heaviest, so more of every tonne cuts and less of it turns to dust.
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Among the hardest garnets
7.5–8.0 on the Mohs scale, above the 6.5–7.5 commonly published for garnet abrasives. At specific gravity 4.00, each grain hits harder than sand, slag or glass.
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Sa 3 on every blasting grade
From coarse 8/12 to fine 120#, every GRM blasting grade reaches Sa 3, the top ISO 8501-1 cleanliness grade: visually clean steel with a uniform metallic colour.
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Low salt, low silica
10–15 ppm water-soluble chlorides and 0.5% free silica, half the 1% line NIOSH recommends. Radioactivity is not detectable.
Clean grains leave clean steel. Coatings last longer.
Coatings fail from underneath. Salt left on blasted steel draws water through the paint film and drives blistering and corrosion under the coating, often long after the job is signed off. GRM Garnet sits 40–60% inside the ISO limits for chlorides and conductivity, so far less salt reaches the steel.
Request a QuoteCount the cost per square metre, not per tonne.
Every abrasive has a price per tonne. What decides the real cost is how fast it cleans, how much is used, what it leaves on the steel and in the air, and what has to be disposed of afterwards.
Other abrasives
- Silica sandCrystalline silica dust causes silicosis. Banned for blast cleaning in Great Britain since 1950.
- Coal and copper slagIndustrial by-products that can carry trace arsenic, beryllium and cadmium.
- Crushed glassLight (SG 2.5) and soft, with the highest respirable dust NIOSH measured.
GRM Garnet
- Faster cleaningGarnet cleaned 36% faster than silica sand in NIOSH field trials.
- Less abrasive per m²30% less by weight than silica sand, and reusable about 6–7 times.
- A natural mineral0.5% free silica, no slag metals, radioactivity not detectable.
In the same NIOSH programme, silica sand had the lowest price per ton and the highest cleaning cost per square foot.
Third-party results describe garnet as an abrasive type, from trials commissioned by the US National Institute for Occupational Safety and Health.
One garnet. Blast, cut and filter.
The hardness, weight and clean chemistry that make GRM Garnet a premium blast abrasive also make it a standard waterjet abrasive and a proven filter medium.
Abrasive blasting
Surface preparation before coating
Steel structures, tanks, pipelines, ships and industrial plant. Sharp, sub-angular grains cut a crisp anchor profile and leave very little salt behind.
Waterjet cutting
Hard enough to cut, kind to the cutting head
Garnet is the standard waterjet abrasive. It cuts quickly without the nozzle and mixing-tube wear of harder synthetics, and dense grains carry the stream’s energy into the cut.
Water filtration
From the fine layer down to the support bed
High density keeps garnet at the bottom of the bed after backwashing, beneath lighter sand and anthracite. GRM’s coarse 4/8 and 2/4 grades take garnet right down to the underdrain, so the whole support bed can be garnet. Hardness resists attrition for a long service life.
SX-EW electrolyte filters
Copper electrowinning
Dual media filters of anthracite over garnet clean the electrolyte before the tankhouse. Fine and support garnet for first fills, top-ups and rebeds, acid-leach tested.
Ten grades. Sa 3 on every blasting grade.
Every grade has a published sieve analysis, so you get a consistent profile and an even feed through the pot or cutting head. Pick a grade to see its typical particle size distribution.
8/80 Alpha Blast
Broad-graded blast abrasive
A wide grading that puts coarse and fine grains to work together. Coarse grains cut depth while finer grains clean the valleys between the peaks, leaving an angular profile for the primer to key into.
25 kg bags
Easy to handle on site and easy to stack, for blasting crews, workshops and waterjet operators.
1 t and 2 t bulk bags
Loose bulk bags for high-volume users, distributors and filter-bed installations.
Published data for every grade
Product data sheet, size chart and safety data sheet, ready for your specification and procurement files.
Specification documents.
Everything your engineers, safety officers and buyers need to approve GRM Garnet.