vapor_cloud, why do you think you're getting metal particles? Some noise and/or resistence when grinding? Not unusual, but normally due to a build up of plant material. I'd think, if a grinder were poorly designed, you'd be more likely to get a bad fit from the side/rim than from teeth. The only way it makes sense (to me, anyway) to build these things is with a template and a CNC machine. My cheapie is definitely a CNC product. If I can buy a CNC made grinder for $12, why use a cheaper production method? Seems like you'd have so many bad ones right out of the box that people would immediately return them or just not buy at all, if tried in a shop. I wish we knew more about the different ways these grinders can be made. I guess it's also possible the type of aluminum/metal being used could be a factor. 'Aircraft grade' aluminum is often advertised, but how do you know what you're actually getting? Anodized aluminum, used in other products like cookware and cameras, is also something to look for. The Mendo, like I said, is a great shredder-lots of sharp teeth. But the holes are 3/16" wide, vs. 1/8" on my smaller no-name. That extra 1/16 of an inch makes a big difference in the consistency of the ground herb. The Mendo grind is great for smoking (unless you want the maximum amount of kief removed), but for vaping, too many larger pieces fall through the bigger holes before the sharp teeth can finish their job. Since my complaint with the no-name was the small size (2 1/8" diameter), the larger Mendo, advertised at 3" but actually 2 7/8", is great for speeding up the initial grind, then the smaller grinder finishes the job (and removes more kief ). Yeah, the Mendo has a nylon gasket, and there's room under the gasket for small particles to hide. The worst feature it has IMO . The no-name screen is tight and has no gasket-great design . The site you linked (mendo warehouse) is the same (and only) guy that sells on ebay. The price recently went up on both sites, so I used a $10 off ebay coupon to save a little on the auction. There is no other source for this grinder online that I can find. Doesn't seem to be Mendo itself selling either, since it was shipped from Texas. You would think there would be another online seller or two for this fine grinder. And neither Mendo or Space Case has a website of their own. In fact, the only grinder companies I can find with a site are Trueblendz and Mix 'n' Ball. Mix'n'Ball makes an excellent (and safe-anodized) grinder (triple screen available too) and is priced less than Mendo and Space Case. At least they have contact info if you wanted to ask any questions. If anyone is interested in the cheap no-name, but good quality grinder, look for Kelly's Great Products on ebay. He's got an affordable 2 screen grinder. I'm still curious about the Space Case. I'd like to directly compare it to the Mendo, but I know a guy who has both brands and the SC has even larger holes than the Mendo, so for the fine grind I like there would be no point. Best Space Case price is vapedaddy.com. A large SC (3 1/2") is a little cheaper than the 3" Mendo. Expect a few weeks delivery time from there though. Back when I was mostly using my Vapolution and herbalAire, I had little need for a grinder. Now that I'm using the SSV and PD, I'm grinding most of my herb. The added benefit to grinding is the pollen screen. I highly recommend the 4 piece (or 5 or 6!) unit to separate your kief. You can always add it back when you want, and in the proportion that suits you.