Herb Grinder Buying Guide: 2-Piece vs 4-Piece, Aluminium vs Stainless Steel
Should I buy a 2-piece or 4-piece herb grinder?
A 2-piece grinder is the simplest: two toothed halves, nothing to clog, but no storage. A 4-piece adds a chamber that collects the ground herb and a fine screen with a bottom chamber that catches kief. Aluminium is light and cheaper; stainless steel is heavier, harder and does not react with plant oils. Pick 2 inch (50 mm) for a pocket and 2.5 inch (63 mm) for the desk.
A grinder is the one accessory that affects every session: an even, fluffy grind burns and vaporises consistently, while a chopped or compressed one burns hot and wastes material. This guide explains the difference between 2-, 3- and 4-piece grinders, the pros and cons of aluminium and stainless steel, what size to choose, and how to keep one turning smoothly. It is written around the RAW and RAW x Hammercraft grinders we stock, but the principles apply to any brand.
2-piece, 3-piece and 4-piece explained
| Type | Parts | What you get | Best for |
|---|---|---|---|
| 2-piece | Lid + toothed base | Fastest, most compact, nothing to clog; the herb stays between the teeth | Pocket carry, dry-herb vaporisers where a coarse grind is fine |
| 3-piece | Lid + teeth + collection chamber | Ground herb falls through holes into a chamber, so the grind is finer and more even | Rolling and general use |
| 4-piece | Lid + teeth + chamber with screen + kief catcher | Everything the 3-piece offers plus a fine mesh that sifts trichomes (kief) into a bottom compartment | Anyone who wants to collect kief; the most common choice |
The screen in a 4-piece is the part that varies most: a finer mesh collects purer kief but more slowly. Some people remove the screen for a coarser, faster grind when using a vaporiser.
Aluminium vs stainless steel
- Aircraft-grade aluminium is the norm: light, easy to machine into sharp teeth and usually anodised for a hard surface. Cheap aluminium grinders can shed flakes as the teeth wear; well-machined ones (the RAW Aluminium Prototype 2-piece and the RAW x Hammercraft 4-piece) do not.
- Stainless steel is heavier and considerably harder, so the teeth stay sharp far longer, and it is non-reactive with sticky plant oils, which many people say keeps flavour cleaner. The RAW Stainless Steel 4-piece 60 mm shredder is the example in our range; expect to pay roughly twice the price of aluminium.
- Avoid painted zinc alloy and acrylic grinders for anything more than occasional use – the teeth round off quickly and paint can chip into the grind.
What size grinder?
| Diameter | Fits | Grinds per fill | Examples listed |
|---|---|---|---|
| 2 in (about 50 mm) | Pocket, small bag | One or two sessions | RAW x Hammercraft 4-piece 2 in |
| 2.5 in (about 63 mm) | Desk drawer, backpack | Several sessions | RAW x Hammercraft 4-piece 2.5 in, RAW Aluminium Prototype 2-piece 2.5 in |
| 60 mm (about 2.4 in) | Desk, shared use | Several sessions; the heavy option | RAW Stainless Steel 4-piece 60 mm |
Details worth checking
- Teeth: diamond or shark-tooth shapes cut rather than crush; more teeth means a finer grind per turn.
- Magnetic lid: keeps the lid aligned and stops spills in a bag.
- Thread quality: coarse, deep threads turn smoothly even with resin on them; fine threads bind.
- Pollen scraper: usually included with 4-piece models for lifting kief from the bottom chamber.
- Origin claims: the RAW x Hammercraft models are described by the brand as machined in Phoenix, Arizona, from American metal; treat such statements as manufacturer claims rather than something we have independently verified.
How to clean a grinder
- Take it apart and tap out loose material; brush the teeth and screen with a stiff, dry brush.
- For a deep clean, put the metal parts in a freezer bag for 20 minutes so the resin turns brittle, then brush again.
- Soak metal parts in isopropyl alcohol (70% or higher) for 20-30 minutes; do not soak acrylic or anything painted.
- Rinse in warm water, dry completely, reassemble. Stainless steel tolerates this indefinitely; anodised aluminium should not be left soaking for hours.
Prices and buying in the UK
On our current listings the RAW x Hammercraft 4-piece costs around £42 in 2 in and £50 in 2.5 in, the RAW Aluminium Prototype 2-piece about £66 and the RAW Stainless Steel 4-piece about £100. Grinders are accessories with no age-restricted or controlled content, though we sell to adults 18+ only as a matter of policy. If you weigh material, the MyWeigh Triton T2 pocket scale (400 g x 0.01 g) is the matching accessory. UK delivery is tracked in 2-4 business days; see the shipping policy.
Quick answers
Is a 4-piece grinder worth it?
If you want to collect kief or prefer a finer, more even grind, yes. If you only need a quick coarse grind for a vaporiser, a good 2-piece is faster and cheaper.
Is stainless steel better than aluminium for a grinder?
It is harder, non-reactive and lasts longer, but it is heavier and costs more. Aluminium is fine if it is well machined and anodised.
What size grinder is standard?
2.5 inch (63 mm) is the standard desk size; 2 inch (50 mm) is the common pocket size.
Why is my grinder hard to turn?
Resin build-up on the threads and teeth. Freeze it for 20 minutes, brush, then soak the metal parts in isopropyl alcohol.
Can I put a grinder in the dishwasher?
Not recommended – detergents and heat can damage anodised finishes and magnets. Use isopropyl alcohol and a brush.
Ready to browse? See metal grinders or the full accessories range.
This article is for informational purposes only, for adults (18+). Cannabis laws differ by country – always follow the rules where you are and use responsibly.
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