Review on Enhanced Grinding with Astro 219 ONYX Grinder 3 Piece: Unleash the Power! by Brad Lovro

Both units work very well and the bits supplied work great too. I bought a second set of bits to separate my aluminum and steel bits and I use these bits on steel and stainless steel and they hold up great. The grinders themselves work very well. As others have mentioned they sometimes get a bit stuck and won't rotate, but rotating them by hand and then pulling the trigger seems to fix them. I've also had issues with the collet being difficult to loosen on a straight bodied tool and I broke both wrenches that came with the kit. I made a set with a thicker 1/8" stock and left some more meat on the sides of the wrench and they held up great. I wish they came with matching wrenches first. Do not drag this tool. I recently gave it to my girlfriend for a stainless steel project she is working on and forgot to tell her not to over tighten it so I had to undo it again. I have one year of warranty left and am planning to send it back to Astro for service to see if they can replace the collet for me. I suspect the burr left over from production is causing the problem for me. I called them to ask what they could do when I first had problems and 1) received an English speaking person within 30 seconds of calling WHO. 2) Covered your warranty policy and estimated repair time from a set of punches with no writing on one of the punches in the set. A quick call later and Astro emailed me. The replacement by a recording on the instrument is free of charge for me. They are based in California so shipping is fast and affordable for me if I ever have to pay for it. I will continue to buy Astro as I build my instrument collection. They're built well enough for my needs and come at relatively affordable prices compared to similar tools from established companies.