1- http://www.allmetric.com/select_an_icon_from_the_product_.htm

2- http://www.almetal.nl/idxti.htm

3- http://www.mdmetric.com/fastindx/indexmstr.htm

4- http://www.thomsonindustries.com/Sections/Products/products_main.asp?PC=7000000&GI=1

5- http://www.ondrives.com/code/products.asp?yesdisplay=T&subcatid=71&catid=4

6- http://www.lenoxlaser.com/flowproducts/setscrews.html

7- http://www.ecs.umass.edu/mie/labs/mda/dlib/machine/weld/weld.html

8- http://www.materialsengineer.com/A-welding.htm

9- http://www.beardmorebros.co.uk/website%20pages/how%20to/how_to_titlepage.htm

10- http://www.weldingvideos.com/index.html

11- http://class.et.byu.edu/mfg130/processes/thermaljoining.htm