http://dogpatch.com/bobp/bobfaq.htm List of northwest workshop resource links (Bob N7RDP's page)
http://www.paciron.com Pacific Iron & Metal South Seattle source of tubing and sheet metal
https://active.boeing.com/assocproducts/surplus/Index.cfm Boeing Surplus (no longer retail, but this is the gateway to online auctions/eBay listings)
http://www.metalshorts.com Metal Shorts - small quantities of new metal stock
http://www.tapplastics.com TAP Plastics - plastic sheets, rods, tubes, etc.