4Specs: has links to many products, but also has discussion groups on a variety of construction / specification related subjects.
Time and Date: A handy-dandy time and date calculator, so if construction starts today and goes for 310 days, it will be completed on what date?, and it answers more.
Principal Metals: is a wholesale distributor of metals. Open to all is their web site which is full of information on 5000 metal alloys and standards.
Masterformat 2004 Transition. Need help with the ‘95’ to ’04 Masterformat switch. Check out this handy section number translator.