Not sure how many of you have ever seen or thought about these before but i found some aluminum extrusions on amazon. I picked up one that i am going to use as a fence on my drill press. I liked how it had all the t slots on it and they work really well for that purpose. they have smooth and one that has little valleys on them as well. The nice thing is they do have a little weight to them so they could make a nice fence and are very smooth and flat. I checked mine and it was spot on. I think it was .000? out and at that amount i dont care anymore. I will post pics once i get the hole thing built seeing as how it is the next thing on my list to make. You can get these in alot of different sizes and lengths. They can be i think about 2x4 in size but i have not seen them i got a 1x2 one for my drill press fence. Hope this helps someone having a nice solid fence or even a rail like this at times can be really nice and the fact it has all the t slots on it make it both easy to mount to things and adaptive.
http://www.amazon.com/gp/product/B00BLQSZMW/ref=ox_sc_sfl_title_5?ie=UTF8&psc=1&smid=A1H481IPHNMK5K
http://www.amazon.com/gp/product/B00BLQSZMW/ref=ox_sc_sfl_title_5?ie=UTF8&psc=1&smid=A1H481IPHNMK5K