Ok, I drew up a design for a sprocket and have a few questions. If I machine it out of 6061 aluminum, should I expect it to get eaten up extremely fast? If so, what should I be looking for, 7075? Also, does anybody have any information on what type of fixture I should look to make to set the sprocket up for machining? I was thinking a square block with the center bored out and the bolt holes drilled/threaded, and just bolting the sprocket stock to it? Any pictures of these fixtures that aren't set up for production jobs would be awesome. All my cutouts will have a chamfer on the edges and I want to be able to flip the stock over and machine both sides without screwing up the work's position. Any help/ideas are appreciated. Thanks, Tim Here is my drawing in mastercam. I was aiming at a design sort of like tags' sprockets.