I found a site that sells clear glass tubes at desired dimensions. They are pretty cheap, here is the site
http://www.tracysworkshop.com/p-15899-corning-pyrex-clear-glass-tubing-heavy-wall-thickness.aspx?affiliateid=10050
http://www.tracysworkshop.com/p-15899-corning-pyrex-clear-glass-tubing-heavy-wall-thickness.aspx?affiliateid=10050