I use three primary sources for Chicago Screws.
Blade tech, mentioned above, but they sell aluminum posts and black stainless steel screws.
Texas Knifemaker's supply sells black stainless posts with black stainless screws (but they're expensive).
http://siteblazer.net/texasknife
I also found this place (Fastener Supply),
http://www.fastener-supply.com/navigate.htm and you can get a TON of screw/posts there for cheap (starting at $13.95 per 100) and in a bunch of different lengths.
Fastener supply only sells brass, however, which many people don't like because it's too bright. Well, I have a little "tip of the day" about that. Take your brass screws and posts and sand the heads of them briefly and lightly to scuff them up a little. Then take a bottle of cold blueing and pour it into a glass dish. Set all of the screws and posts inside the bleuing solution. After a couple of hours the brass screws and posts will turn black. The black corrosion on the outside will come off easily, just take the screws and posts out of the blueing and put them into a strainer and shake them as you pour water over them. Then dry them off with a paper towel. The brass becomes antiqued quite quickly at that point, leaving a very pleasant looking patina (or, shall I say, I quite like it).
Matt
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