http://www2.worksafebc.com/Publications/Multimedia/Videos.asp?ReportID=35144
http://www.aee.vt.edu/teacher-resources/lab-safety-resources/pcircularsaw.pdf
types of circular saw blades
http://sawbladesessentials.blogspot.com/2011/11/six-common-types-of-circular-saw-blades.html
