"Construction" section on front page

I think it'd be valuable to add a section on fasteners (ex. what you'd find in Carroll Smith's book, Kent's MEng Handbook, or aircraft handbooks), materials (alu, steel, titanium, mag, plastics, and composites), and something on tools and welding. A start being:

Construction

Fasteners

 >Nuts
 >Bolts
 >Rivets
 >Safetying
 > ...

Materials

 >Aluminum Alloys
 >Ferrous Alloys
 >Magnesium Alloys
 >Titanium Alloys
 >Plastics
 >Composites
 > ...

Tools

 >Hand Tools
 >Metal-Cutting Tools
 >Drilling, Taps, and Dies
 >Sheet Metal Tools
 >Forming
   >Press-Brake Forming
   >Stretch Forming
   > ...
 > ...

Plumbing

 >Solid Lines
 >Flexible Lines
 >Connections
 > ...

Sorry for the rough formatting, this was just an idea dump