Metal herb grinders
The metal herb grinder,machined properly.
Most metal herb grinders are a die-cast shell with soft teeth and a lid that drifts out of line inside a month. Ours are cut from solid aircraft-grade aluminium on a CNC machine — holds its tolerance for years, because a grinder is a tool someone reaches for every single day.
How a grinder actually works
Two milled plates face each other, each carrying a set of teeth offset so they pass without touching. Material sits between them and a half-turn shears it evenly rather than crushing it. The whole thing lives or dies on that tolerance: teeth cut too shallow tear instead of slice, and a body machined loosely lets the plates wander until they bind.
A magnet in the lid holds the halves in register while you turn them, which is why a good grinder keeps its alignment for years and a cheap one starts grinding against itself. Everything past that — extra chambers, screens, catch trays — is about what happens to the material after it has been cut.
2-part or 4-piece herb grinder
The only real decision. The 2-part is a compact everyday carry. The 4-piece herb grinder adds a stainless steel kief-catcher screen and a pollen chamber underneath — so fine material collects separately rather than being lost in the teeth.
Two chambers
2-Part Premium Grinder
- Grinding teeth and a single catch chamber
- Magnetic lid, diamond-cut teeth
- Aircraft-grade aluminium body
- Eight anodized colours
Best for: Everyday carry. Fewer parts, less to clean, the shape most people picture when they think of a grinder.
$50.00 single·$6.75 at 1,000
Four chambers
4-Part Premium Grinder
- Grinding teeth, catch chamber, kief-catcher screen and pollen well
- High-micron stainless steel screen with kief catcher tray
- Scraper included
- Aircraft-grade aluminium body
Best for: Anyone who wants the fine material separated by the kief catcher and kept rather than lost in the teeth.
$75.00 single·$9.50 at 1,000
Three sizes. Same precision.
Every size is CNC-machined from the same aluminium billet, with the same diamond-cut teeth and rare-earth magnets. The only difference is how much material you want to grind in one go.
Small
42mm
Fits in a pocket, grinds enough for one or two people. The size most people picture when they think "everyday carry."
Medium
50 / 56mm
The sweet spot. Enough capacity for a group session without taking up pocket space. Most popular size for branded runs.
Large
63 / 75mm
For heavy use, dense flower, or when you want the grinder to feel substantial in the hand. 63mm is standard large; 75mm is statement size.
What you are actually paying for
The size. A large herb grinder — 63 mm diameter and above — moves more material per turn and handles dense product without packing. The compact 2-part suits a pocket; the large 4-piece grinder with kief catcher suits a full session. Both are machined to the same tolerance; size is purely a preference.
The material. Aircraft-grade aluminium is stiff enough to hold a machined edge. Die-cast alloy and plastic round off, and once the teeth are dull the grinder is finished — there is no sharpening it.
The teeth. Diamond-cut teeth are milled, not moulded, so every one sits at the same height and the load spreads evenly across the plate.
The finish. Anodizing hardens the surface rather than sitting on top of it like paint, which is why an anodized body keeps its colour through years of pocket wear.
The screen. On 4-piece herb grinders, a high-micron stainless steel screen decides what falls through to the kief catcher tray below. Woven stainless steel holds its shape; cheap mesh stretches and stops sorting anything at all.
Then put your nameright on the lid.
We do not sell blank stock. Every grinder we machine goes out carrying somebody's brand — 3D metal engraving in gold, silver, black or rose gold, laser engraving, full-colour UV printing or polycarbonate stickers. Dispensaries, record labels, podcasts and artists all order the same bodies; only the lid changes.
There is no minimum order, so ten pieces and ten thousand get the same machining and the same finishes. You see a free digital proof before anything is cut — see how that compares to other custom grinder suppliers.
GMI vs other metal herb grinders
Most custom grinder suppliers buy stock grinders from overseas factories and print your logo on top. GMI machines every grinder from raw aluminium billet. The difference shows up in weight, tooth sharpness, thread tolerance, and how the finish holds up after a year of daily carry.
| Feature | GMI | Typical supplier |
|---|---|---|
| Source | CNC-machined from billet | Die-cast import |
| Material | 6061 aircraft-grade aluminium | Zinc alloy / cast metal |
| Teeth | Diamond-cut, milled | Moulded, rounded |
| Finish | Anodized (8 colours) | Painted / coated |
| Branding | 3D engraving, laser, UV print | Sticker / pad print |
| Minimum order | 1 unit | 25–500 units |
| Proof | Free digital proof in 1 day | — |
Metal Herb Grinder FAQ
What is the best metal herb grinder?
The best metal herb grinder is CNC-machined from aircraft-grade aluminium with diamond-cut teeth, a rare-earth magnet, and a high-micron steel screen. GMI machines every grinder from raw billet — not die-cast alloy — so the teeth hold their edge and the threads stay tight for years.
What size herb grinder should I get?
A 45mm grinder suits everyday carry. A 63mm grinder handles more material per turn and is better for dense flower or group sessions. Both sizes are machined to the same tolerance — size is purely preference.
Is a 4-piece grinder better than a 2-piece?
A 4-piece grinder adds a kief-catcher screen and pollen chamber underneath. If you want to collect fine material separately, yes. If you want something compact and easy to clean, the 2-piece is the better choice.
How do I clean a metal herb grinder?
Disassemble the grinder, soak the metal parts in isopropyl alcohol for 30 minutes, then scrub with a soft brush. The anodized finish holds up to alcohol cleaning — unlike painted grinders, which will strip.
Can I put my logo on a metal herb grinder?
Yes. GMI offers 3D metal engraving (gold, silver, black, rose gold), laser engraving, full-colour UV printing, and polycarbonate stickers. Every method is permanent — the mark won't rub off like a decal.
How long do custom herb grinders take?
Free digital proof within 1 business day. Production runs 10-20 business days after approval. Rush shipping is free on every order.