This guide covers glass and hardware for use with legal products only, in line with your state's laws. TAG makes no health claims about any material you choose to use.
You may be wondering if a grinder is a good investment. Perhaps you are poking around with some old scissors wondering if you should upgrade. We can tell you this: a metal herb 
grinder is one of the best investments a frequent user can make.
How Metal Herb Grinders Help You
Metal herb grinders speed up and simplify the process of breaking down your dry herb. They also make it much easier to conserve your material when it is finely and evenly ground.
When you pull material apart by hand, some of it sticks to your fingers, and you lose it before it ever reaches the bowl. A grinder keeps that material where it belongs.
When herb is ground evenly, it packs more consistently into a bowl or rolling papers. A consistent grind also improves airflow, which gives you a more even, controlled burn.
In short, metal herb grinders give you more control over how evenly and smoothly your material burns.
Your grinder is also a handy way to store small amounts of material when you are not quite ready to use it. Our collection of herb grinders is here:
https://www.thickassglass.com/collections/grinders
How Grinders Are Made
Grinders are:
- Made out of metal or plastic
- Built with at least two interlocking pieces that form upper and lower chambers
- Fitted with teeth in the upper chamber that slice and grind any dry herb you insert
- Designed so ground material falls through small holes into the lower chamber
- Varied in the number and shape of teeth by brand
Different Chambers
Many grinders on the market have more than just two chambers.
A common option is the four-piece grinder. The four-piece design typically has a bottom chamber separated from the others by a metal mesh screen.
This mesh screen catches the fine pollen that falls off your material while grinding. The grinder then stores your ground material in a separate chamber so it can be used whenever you like.
You can also find five-piece grinders with a second, finer mesh screen that further separates the ground material you place inside.
Why Metal Over Plastic
Metal grinders hold an edge on their teeth far longer than plastic ones, so they keep cutting cleanly instead of tearing at your material. Plastic teeth wear down and can snap under a dense load, and small plastic fragments sometimes end up mixed in with what you ground. A solid aluminum or metal body also stands up to daily use and years of grinding without the housing cracking or the threads stripping, which is a big part of why it pays for itself over time.
Maintenance
Always clean your metal herb grinder routinely to keep it from clogging, and never use a dirty grinder. Resin builds up on the teeth and in the threads over time, which makes the grinder stiff to turn and less effective. A quick brush after regular use, plus an occasional soak in isopropyl alcohol for the metal parts, keeps everything turning smoothly and the mesh screen clear.
Sizes
Grinders come in a variety of sizes. Size does not affect function. The size you choose only depends on how much material you would like to grind at one time.
You do not necessarily need a $90 metal herb grinder. There are levels of pricing, but most users can get away with something under $50.